REPO: Force download if the kara if unavlailable

If a kara is present on disk but is marked as unavailable, it would not be downloaded. This MR fix it, if a kara is marked as unavailable it will be downloaded anyway (may be filtered by user URI…)

inc/lektor/database.h

@@ -73,6 +73,7 @@ bool database_get_kara_mtime_path   (lkt_db *db, char filepath[PATH_MAX], uint64
 bool database_get_kara_duration_path(lkt_db *db, char filepath[PATH_MAX], uint64_t *duration);
 bool database_is_kara_mkv           (lkt_db *db, char filepath[PATH_MAX], bool *valid_mkv);
 bool database_is_kara_like          (lkt_db *db, int id, const char *str);
+bool database_is_kara_available     (lkt_db *db, int id, bool *avail);
 void database_cache_kara            (lkt_db *db, int id);
 void database_cache_kara_magic      (lkt_db *db, int id);