fix: remove internal Jira URL from codebase

Remove zipstack.atlassian.net reference from visitran.py comment.

Author: wicky-zipstack

backend/visitran/visitran.py

@@ -492,7 +492,6 @@ def draw_dag(self) -> None:
             This causes an Runtime error when
             calling this from django.
             So suppressing generation of dag.png when calling this from django.
-            See: https://zipstack.atlassian.net/browse/OR-109
             """
             with warnings.catch_warnings():
                 warnings.simplefilter("ignore")