fix: [postgres] display service name upon error when not find containers and running ``sql`` action

postgres/actions/relations/postgres-database/sql

@@ -97,12 +97,10 @@ set -e
 containers="$(get_running_containers_for_service "$RELATION_TARGET_SERVICE")"
 
 if [ -z "$containers" ]; then
-    err "No containers running for service $DARKYELLOW$service$NORMAL."
+    err "No containers running for service $DARKYELLOW$RELATION_TARGET_SERVICE$NORMAL."
     exit 1
 fi
 
-
-
 ## XXXvlab: taking first container is probably not a good idea
 container_id="$(echo "$containers" | head -n 1)"
 docker exec -i -u 0 \