You can run
echo 0 | sudo tee /sys/class/timed_output/vibrator/amp
in the terminal / in the adb-shell.
This will disable the vibration until the next boot. To re-enable it, you can use
echo 70 | sudo tee /sys/class/timed_output/vibrator/amp
If you want to disable vibration automatically on boot you can put the following text in a new .conf-file (e.g.
start on runlevel 
stop on starting rc RUNLEVEL=
echo 0 > /sys/class/timed_output/vibrator/amp
I am not totally sure if this the best/proper way of doing this, but it should work.