Fixing pylint | removed duplicate imports

Author: snyaggarwal

core/mappings/models.py

@@ -224,7 +224,6 @@ def to_source_name(self):
         if source:
             return source.mnemonic
         if self.to_source_url:
-            from core.common.utils import to_parent_uri
             parent_uri = to_parent_uri(self.to_source_url)
             if parent_uri:
                 return parent_uri.rstrip('/').split('/')[-1]