Change an Alembic doc link to http from https

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docs/index.rst

@@ -145,7 +145,7 @@ After the extension is initialized, a ``db`` group will be added to the command-
     Initializes migration support for the application. The optional ``--multidb`` enables migrations for multiple databases configured as `Flask-SQLAlchemy binds <https://pythonhosted.org/Flask-SQLAlchemy/binds.html>`_.
 
 - ``flask db revision [--message MESSAGE] [--autogenerate] [--sql] [--head HEAD] [--splice] [--branch-label BRANCH_LABEL] [--version-path VERSION_PATH] [--rev-id REV_ID]``
-    Creates an empty revision script. The script needs to be edited manually with the upgrade and downgrade changes. See `Alembic's documentation <https://alembic.zzzcomputing.com/en/latest/index.html>`_ for instructions on how to write migration scripts. An optional migration message can be included.
+    Creates an empty revision script. The script needs to be edited manually with the upgrade and downgrade changes. See `Alembic's documentation <http://alembic.zzzcomputing.com/en/latest/index.html>`_ for instructions on how to write migration scripts. An optional migration message can be included.
 
 - ``flask db migrate [--message MESSAGE] [--sql] [--head HEAD] [--splice] [--branch-label BRANCH_LABEL] [--version-path VERSION_PATH] [--rev-id REV_ID]``
     Equivalent to ``revision --autogenerate``. The migration script is populated with changes detected automatically. The generated script should to be reviewed and edited as not all types of changes can be detected automatically. This command does not make any changes to the database, just creates the revision script.