fix(tests): force gzip output to prevent pod crashlooping in case of restart

Author: razvan

tests/templates/kuttl/oidc-opa/30_nifi.yaml.j2

@@ -59,7 +59,7 @@ spec:
           - -euo
           - pipefail
           args:
-          - cp /tmp/flow.json /stackable/data/database/flow.json && gzip /stackable/data/database/flow.json
+          - cp /tmp/flow.json /stackable/data/database/flow.json && gzip -f /stackable/data/database/flow.json
           volumeMounts:
           - mountPath: /stackable/data/database
             name: database-repository