Make system revert to previous governor instead of "powersave"

See issue 214.

example/gamemode.ini

@@ -5,7 +5,7 @@ reaper_freq=5
 ; The desired governor is used when entering GameMode instead of "performance"
 desiredgov=performance
 ; The default governer is used when leaving GameMode instead of restoring the original value
-defaultgov=powersave
+;defaultgov=powersave
 
 ; The iGPU desired governor is used when the integrated GPU is under heavy load
 igpu_desiredgov=powersave