fix: undefined variable $response in DAV storage #13645

Job	Run time
changes	5s
integration-sqlite (capabilities_features, 8.1, main)	1m 16s
integration-sqlite (collaboration_features, 8.1, main)	2m 27s
integration-sqlite (comments_features, 8.1, main)	1m 56s
integration-sqlite (dav_features, 8.1, main)	5m 32s
integration-sqlite (features, 8.1, main)	6m 42s
integration-sqlite (federation_features, 8.1, main)	3m 3s
integration-sqlite (--tags ~@large files_features, 8.1, main)	8m 3s
integration-sqlite (filesdrop_features, 8.1, main)	1m 35s
integration-sqlite (openldap_features, 8.1, main)	1m 32s
integration-sqlite (openldap_numerical_features, 8.1, main)	1m 40s
integration-sqlite (ldap_features, 8.1, main)	1m 51s
integration-sqlite (remoteapi_features, 8.1, main)	1m 30s
integration-sqlite (setup_features, 8.1, main)	52s
integration-sqlite (sharees_features, 8.1, main)	3m 2s
integration-sqlite (sharing_features, 8.1, main)	11m 36s
integration-sqlite (videoverification_features, 8.1, main)	4m 10s
integration-sqlite-summary	10s
	57m 2s

Provide feedback