remove awful unneeded __get_env_var function

Author: rerpha

src/server_common/helpers.py

@@ -48,19 +48,11 @@ def get_macro_values() -> Dict[str, str]:
     print("Defined macros: " + str(macros))
     return macros
 
-
-def _get_env_var(name: str) -> str:
-    try:
-        return os.environ[name]
-    except:
-        return ""
-
-
 MACROS = {
-    "$(MYPVPREFIX)": _get_env_var("MYPVPREFIX"),
-    "$(EPICS_KIT_ROOT)": _get_env_var("EPICS_KIT_ROOT"),
-    "$(ICPCONFIGROOT)": _get_env_var("ICPCONFIGROOT"),
-    "$(ICPVARDIR)": _get_env_var("ICPVARDIR"),
+    "$(MYPVPREFIX)": os.environ.get("MYPVPREFIX", ""),
+    "$(EPICS_KIT_ROOT)": os.environ.get("EPICS_KIT_ROOT", ""),
+    "$(ICPCONFIGROOT)": os.environ.get("ICPCONFIGROOT", ""),
+    "$(ICPVARDIR)": os.environ.get("ICPVARDIR", ""),
 }
 CONTROL_SYSTEM_PREFIX = MACROS["$(MYPVPREFIX)"] + "CS:"
 PVPREFIX_MACRO = "$(MYPVPREFIX)"