Revert "fix units with empty strings"

This reverts commit 3d58f5f.

Author: kecnry

lcviz/utils.py

@@ -281,7 +281,7 @@ def to_object(self, data_or_subset):
 
             if len(values) and isinstance(values[0], Time):
                 values = Time(values.base)
-            elif hasattr(component, 'units') and component.units not in ("None", ""):
+            elif hasattr(component, 'units') and component.units != "None":
                 values = u.Quantity(values, component.units)
 
             if component_id.label not in names: