Update Comment Typos

update 'the' to 'then' on line 34
update 'customwidget' to 'custom widget' to match reference in comment on line 72
Update 'windows' to 'Windows' on line 65 to match previous reference on line 31

python/__init__.py

@@ -31,7 +31,7 @@ def setupenv():
     Set the environment for Windows based on the .vars files from the
     OSGeo4W package format.
     """
-    # If the prefix path is already set the we don't do any more path setup.
+    # If the prefix path is already set then we don't do any more path setup.
     if os.getenv('QGIS_PREFIX_PATH'):
         return
 
@@ -62,7 +62,7 @@ def setupenv():
 
 
 if os.name == 'nt':
-    # On windows we need to setup the paths before we can import
+    # On Windows we need to setup the paths before we can import
     # any of the QGIS modules or else it will error.
     setupenv()
 
@@ -77,7 +77,7 @@ def setupenv():
 try:
     import qgis.gui
     widget_list = dir(qgis.gui)
-    # remove widgets that are not allowed as customwidgets (they need to be manually promoted)
+    # remove widgets that are not allowed as custom widgets (they need to be manually promoted)
     skip_list = ['QgsScrollArea']
     for widget in widget_list:
         if widget.startswith('Qgs') and widget not in skip_list: