Merge "Use TOX_CONSTRAINTS_FILE"

tox.ini

@@ -6,7 +6,7 @@ ignore_basepython_conflict = true
 [testenv]
 basepython = python3
 deps =
-  -c{env:UPPER_CONSTRAINTS_FILE:https://opendev.org/openstack/requirements/raw/branch/master/upper-constraints.txt}
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
   -r{toxinidir}/test-requirements.txt
   -r{toxinidir}/requirements.txt
 commands =