emscripten: Fix alt key being a nav key

src/video/emscripten/SDL_emscriptenevents.c

@@ -578,8 +578,7 @@ Emscripten_HandleKey(int eventType, const EmscriptenKeyboardEvent *keyEvent, voi
                  keyEvent->keyCode == 39 /* right */ ||
                  keyEvent->keyCode == 40 /* down */ ||
                  (keyEvent->keyCode >= 112 && keyEvent->keyCode <= 135) /* F keys*/ ||
-                 keyEvent->ctrlKey ||
-                 keyEvent->altKey;
+                 keyEvent->ctrlKey;
 
     if (eventType == EMSCRIPTEN_EVENT_KEYDOWN && SDL_GetEventState(SDL_TEXTINPUT) == SDL_ENABLE && !is_nav_key)
         prevent_default = SDL_FALSE;