fixes minor issue with strict diff of network config (#21436)

strips leading and trailing spaces for line comparision to prevent
fails positiives

lib/ansible/module_utils/netcfg.py

@@ -247,9 +247,9 @@ class NetworkConfig(object):
         updates = list()
         for index, line in enumerate(self.items):
             try:
-                if line != other[index]:
+                if str(line).strip() != str(other[index]).strip():
                     updates.append(line)
-            except IndexError:
+            except (AttributeError, IndexError):
                 updates.append(line)
         return updates