config: fix string parsing

common.c

@@ -1123,6 +1123,7 @@ config_tokenizer_next (struct config_tokenizer *self, struct error **e)
 			config_tokenizer_error (self, e, "not a valid UTF-8 string");
 			return CONFIG_T_ABORT;
 		}
+		return CONFIG_T_STRING;
 	}
 
 	char *end;