fix missing semicolon

Author: alukach

applications/argocd/staging/applications/montandon-eoapi/stac-auth-proxy/montandon_filters.py

@@ -19,7 +19,7 @@
 
 logger = logging.getLogger(__name__)
 
-if not (UPSTREAM_URL := os.environ.get("UPSTREAM_URL"))
+if not (UPSTREAM_URL := os.environ.get("UPSTREAM_URL")):
     raise ValueError("Failed to retrieve upstream URL")