Add default: break; to switches on SDL_Event::type

This is just a nice-to-have, as `SDL_Event::type` in an `Uint32`, so there are no
compiler errors about not handling all `SDL_EventType` enum values.

test/testcamera.c

@@ -202,6 +202,8 @@ int SDL_AppEvent(const SDL_Event *event)
             SDL_Log("Camera denied!");
             SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR, "Camera permission denied!", "User denied access to the camera!", window);
             return -1;
+        default:
+            break;
     }
 
     return SDLTest_CommonEventMainCallbacks(state, event);