fix: cloudsync_network_check_changes must return 0 if there are no available changes, not only rc = SQLITE_OK, because it is a SELECT statement

Author: andinux

src/network.c

@@ -298,6 +298,7 @@ int network_set_sqlite_result (sqlite3_context *context, NETWORK_RESULT *result)
     switch (result->code) {
         case CLOUDSYNC_NETWORK_OK:
             sqlite3_result_error_code(context, SQLITE_OK);
+            sqlite3_result_int(context, 0);
             rc = 0;
             break;