updae source to 2.0.9 source

Edward Rudd

2019-04-09 9cd2e9ec8fc0127393dfce9c0359d500c8c238be

 source/src/video/emscripten/SDL_emscriptenopengles.c

@@ -60,6 +60,8 @@
    LOAD_FUNC(eglWaitNative);
    LOAD_FUNC(eglWaitGL);
    LOAD_FUNC(eglBindAPI);
    LOAD_FUNC(eglQueryString);
    LOAD_FUNC(eglGetError);
    
    _this->egl_data->egl_display = _this->egl_data->eglGetDisplay(EGL_DEFAULT_DISPLAY);
    if (!_this->egl_data->egl_display) {