GL|Fixed: Always apply frame rate limiting if requested

If the requested refresh rate is lower than what the system is capable
of producing, an additional wait is applied right before showing the
frame.

doomsday/engine/portable/src/gl_main.c

@@ -221,13 +221,10 @@ void GL_DoUpdate(void)
     LIBDENG_ASSERT_IN_MAIN_THREAD();
     LIBDENG_ASSERT_GL_CONTEXT_ACTIVE();
 
-    if(Window_ShouldRepaintManually(Window_Main()))
-    {
-        // Wait until the right time to show the frame so that the realized
-        // frame rate is exactly right.
-        glFlush();
-        DD_WaitForOptimalUpdateTime();
-    }
+    // Wait until the right time to show the frame so that the realized
+    // frame rate is exactly right.
+    glFlush();
+    DD_WaitForOptimalUpdateTime();
 
     // Blit screen to video.
     Window_SwapBuffers(theWindow);