remove unused variables

apps/files_encryption/lib/cryptstream.php

apps/files_external/lib/smb.php

apps/files_external/tests/ftp.php

apps/files_external/tests/google.php

apps/files_external/tests/smb.php

apps/files_external/tests/swift.php

apps/files_external/tests/webdav.php

apps/gallery/lib/album.php

apps/gallery/lib/managers.php

apps/gallery/lib/tiles.php

apps/media/lib_ampache.php

apps/media/lib_collection.php

apps/media/lib_media.php

apps/remoteStorage/lib_remoteStorage.php

lib/archive/zip.php

lib/filecache/update.php

lib/filestorage/common.php

lib/group/database.php

lib/group/dummy.php

lib/group/example.php