Default to non-threaded export setting for the web

platform/web/export/export_plugin.cpp

@@ -346,7 +346,7 @@ void EditorExportPlatformWeb::get_export_options(List<ExportOption> *r_options)
 	r_options->push_back(ExportOption(PropertyInfo(Variant::STRING, "custom_template/release", PROPERTY_HINT_GLOBAL_FILE, "*.zip"), ""));
 
 	r_options->push_back(ExportOption(PropertyInfo(Variant::BOOL, "variant/extensions_support"), false)); // Export type.
-	r_options->push_back(ExportOption(PropertyInfo(Variant::BOOL, "variant/thread_support"), true)); // Thread support (i.e. run with or without COEP/COOP headers).
+	r_options->push_back(ExportOption(PropertyInfo(Variant::BOOL, "variant/thread_support"), false)); // Thread support (i.e. run with or without COEP/COOP headers).
 	r_options->push_back(ExportOption(PropertyInfo(Variant::BOOL, "vram_texture_compression/for_desktop"), true)); // S3TC
 	r_options->push_back(ExportOption(PropertyInfo(Variant::BOOL, "vram_texture_compression/for_mobile"), false)); // ETC or ETC2, depending on renderer