Fix ZipIO crash when reused (and possible leaks).

platform/javascript/export/export_plugin.cpp

@@ -33,7 +33,8 @@
 #include "core/config/project_settings.h"
 
 Error EditorExportPlatformJavaScript::_extract_template(const String &p_template, const String &p_dir, const String &p_name, bool pwa) {
-	zlib_filefunc_def io = zipio_create_io();
+	Ref<FileAccess> io_fa;
+	zlib_filefunc_def io = zipio_create_io(&io_fa);
 	unzFile pkg = unzOpen2(p_template.utf8().get_data(), &io);
 
 	if (!pkg) {