htable: Fix memory leak when reloading an empty htable from database

src/modules/htable/ht_db.c

@@ -247,6 +247,7 @@ int ht_db_load_table(ht_t *ht, str *dbtable, int mode)
 		} else {
 			if(RES_ROW_N(db_res)==0)
 			{
+				ht_dbf.free_result(ht_db_con, db_res);
 				LM_DBG("Nothing to be loaded in hash table\n");
 				return 0;
 			}