fix for using .rc files

src/build_settings.cpp

@@ -1822,6 +1822,7 @@ gb_internal bool init_build_paths(String init_filename) {
 		if (bc->resource_filepath.len > 0) {
 			bc->build_paths[BuildPath_RES] = path_from_string(ha, bc->resource_filepath);
 			if (!string_ends_with(bc->resource_filepath, str_lit(".res"))) {
+				bc->build_paths[BuildPath_RES].ext = copy_string(ha, STR_LIT("res"));
 				bc->build_paths[BuildPath_RC]      = path_from_string(ha, bc->resource_filepath);
 				bc->build_paths[BuildPath_RC].ext  = copy_string(ha, STR_LIT("rc"));
 			}