Don't set gating status twice when creating update (#4219)

On the normal path of creating an update - where it is created
and immediately submitted to updates-testing - we're setting
the gating status twice. We call `set_request`, which calls
`update_test_gating_status()` if the request is updates-testing
and gating is required, and then almost immediately afterwards,
we straight up set the status to 'waiting'. That doesn't make
much sense.

This changes things so that the `new()` method doesn't hard set
the status to 'waiting' if it's calling `set_request` and the
request is to updates-testing, as is usually the case.

Signed-off-by: Adam Williamson <awilliam@redhat.com>

bodhi/server/models.py

@@ -2371,12 +2371,17 @@ def new(cls, request, data):
         log.debug(f"Triggering db commit for new update {up.alias}.")
         db.commit()
 
+        # track whether to set gating status shortly...
+        setgs = config.get('test_gating.required')
         # The request to testing for side-tag updates is set within the signed consumer
         if not data.get("from_tag"):
             log.debug(f"Setting request for new update {up.alias}.")
             up.set_request(db, req, request.user.name)
+            if req == UpdateRequest.testing:
+                # set_request will update gating status if necessary
+                setgs = False
 
-        if config.get('test_gating.required'):
+        if setgs:
             log.debug(
                 'Test gating required is enforced, marking the update as waiting on test gating')
             up.test_gating_status = TestGatingStatus.waiting