If there's an in game command for it, I don't know it. There wasn't one when I last played.
Unload config. Then look at Windower4\plugins\settings for a file called config.xml. Open it, and find the line:
Code
<AnimationFrameRate>0</AnimationFrameRate>
It will possibly have this comment below it.
Code
<!--2 for 30 FPS, 1 for 60 FPS, 0 for uncapped frame rates-->
As set the value according to the comment for your desired framerate.
Save the file, then load config. Check FPS.
DISCLAIMER: I haven't played in 3~4 months, the config. xml file may have changed.