qtplasmac-materials: Change to raw strings to fix Python SyntaxWarning

This commit just aligns master with the changes (ab2c16b and 8beac1b) made to this file in 2.9 (they were fixed different ways at different times).  Raw strings makes the intent easier to understand for future developers.

src/emc/usr_intf/qtplasmac/qtplasmac-materials.py

@@ -281,40 +281,40 @@ def on_convert_clicked(self):
                         self.materialCutM = 'CUT_MODE           = 1'
                     elif 'PlasmaTool' in line:
                         valid = True
-                    elif line.startswith('Tool\\ number'):
+                    elif line.startswith(r'Tool\ number'):
                         b = line.split('=')[1]
                         self.materialNum = f'[MATERIAL_NUMBER_{b.strip().replace("]","")}]'
                     elif line.startswith('Name='):
                         b = line.split('=', 1)[1]
                         self.materialName = f'NAME               = {b.strip()}'
-                    elif line.startswith('Kerf\\ width'):
+                    elif line.startswith(r'Kerf\ width'):
                         b = line.split('=', 1)[1]
                         self.materialKerf = f'KERF_WIDTH         = {float(b.strip()) / self.divisor:.{self.precision}f}'
-                    elif line.startswith('Pierce\\ height'):
+                    elif line.startswith(r'Pierce\ height'):
                         b = line.split('=', 1)[1]
                         self.materialPierceH = f'PIERCE_HEIGHT      = {float(b.strip()) / self.divisor:.{self.precision}f}'
-                    elif line.startswith('Pierce\\ delay'):
+                    elif line.startswith(r'Pierce\ delay'):
                         b = line.split('=', 1)[1]
                         self.materialPierceD = f'PIERCE_DELAY       = {b.strip()}'
-                    elif line.startswith('Cut\\ height'):
+                    elif line.startswith(r'Cut\ height'):
                         b = line.split('=', 1)[1]
                         self.materialCutH = f'CUT_HEIGHT         = {float(b.strip()) / self.divisor:.{self.precision}f}'
-                    elif line.startswith('Feed\\ rate'):
+                    elif line.startswith(r'Feed\ rate'):
                         b = line.split('=', 1)[1]
                         self.materialCutS = f'CUT_SPEED          = {float(b.strip()) / self.divisor:.0f}'
-                    elif line.startswith('Cut\\ current') or (line.startswith('Preset\\ current') and self.materialCutA == 'CUT_AMPS           = 0'):
+                    elif line.startswith(r'Cut\ current') or (line.startswith(r'Preset\ current') and self.materialCutA == 'CUT_AMPS           = 0'):
                         b = line.split('=', 1)[1]
                         self.materialCutA = f'CUT_AMPS           = {b.strip()}'
-                    elif line.startswith('Cut\\ voltage') or (line.startswith('Preset\\ volts') and self.materialCutV == 'CUT_VOLTS          = 0'):
+                    elif line.startswith(r'Cut\ voltage') or (line.startswith(r'Preset\ volts') and self.materialCutV == 'CUT_VOLTS          = 0'):
                         b = line.split('=', 1)[1]
                         self.materialCutV = f'CUT_VOLTS          = {b.strip()}'
-                    elif line.startswith('Pause\\ at\\ end\\ of\\ cut'):
+                    elif line.startswith(r'Pause\ at\ end\ of\ cut'):
                         b = line.split('=', 1)[1]
                         self.materialPauseE = f'PAUSE_AT_END       = {b.strip()}'
-                    elif line.startswith('Gas\\ pressure') or (line.startswith('Preset\\ Air\\ Pressure') and self.materialGasP == 'GAS_PRESSURE       = 0'):
+                    elif line.startswith(r'Gas\ pressure') or (line.startswith(r'Preset\ Air\ Pressure') and self.materialGasP == 'GAS_PRESSURE       = 0'):
                         b = line.split('=', 1)[1]
                         self.materialGasp = f'GAS_PRESSURE       = {b.strip()}'
-                    elif line.startswith('Cut\\ mode') or (line.startswith('Preset\\ mode') and self.materialCutM == 'CUT_MODE           = 1'):
+                    elif line.startswith(r'Cut\ mode') or (line.startswith(r'Preset\ mode') and self.materialCutM == 'CUT_MODE           = 1'):
                         b = line.split('=', 1)[1]
                         self.materialCutM = f'CUT_MODE           = {b.strip()}'
                     count += 1