fix gpk error

fix gpk error caused by images or incorrect shutdown

vnc-version/Dockerfile

@@ -100,7 +100,7 @@ RUN printf '%s\n' \
 
 # this won't work if you have 99 monitors, 98 monitors is fine though // don't forget to remove the lock file incase you shut down incorrectly or create an image.
 RUN printf '%s\n%s\n%s\n\n' \
-'sudo rm -rf /tmp/.X99-lock' \
+'sudo rm -f /tmp/.X99-lock' \
 'export DISPLAY=:99' \
 'vncserver -kill :99 || true' \
 'vncserver -geometry 1920x1080 -depth ${DEPTH} -xstartup ~/.vnc/xstartup :99' > vnc.sh