Add NO_CUSTOM_LEVELS guard around EDITORMODE in deltaloop()

Otherwise a NO_CUSTOM_LEVELS build would fail. Also I got rid of the
'graphics.flipmode = false;' in the fixed loop because I don't think it
does anything.

desktop_version/src/main.cpp

@@ -395,10 +395,12 @@ void deltaloop()
         case PRELOADER:
             preloaderrender();
             break;
+#if !defined(NO_CUSTOM_LEVELS)
         case EDITORMODE:
             graphics.flipmode = false;
             editorrender();
             break;
+#endif
         case TITLEMODE:
             titlerender();
             break;
@@ -494,7 +496,6 @@ void fixedloop()
             break;
 #if !defined(NO_CUSTOM_LEVELS)
         case EDITORMODE:
-            graphics.flipmode = false;
             //Input
             editorinput();
             ////Logic