Clear integrity check

When the casper log shows an integrity check which usually takes a long time the following steps can help clearing this check.

Step1:

stop casper-node
sudo systemctl stop casper-node-launcher

Step2:

delete /var/lib/casper/casper-node/initializer.pid
sudo rm /var/lib/casper/casper-node/initializer.pid

Step3:

start casper-node
sudo systemctl start casper-node-launcher