fix out of space error on /var/run
fix out of space error on /var/run

When running the war file form /var/run will get an out of space error.
This error is described here with a potential workaround:
https://issues.jenkins-ci.org/browse/JENKINS-11366
it was fixed by
https://github.com/jenkinsci/packaging/commit/b98f3a38238b70d4ab2fd9183a7e8b6b9db39aff
and current implementation was applied to this commit:
https://github.com/jenkinsci/packaging/blob/93fb4c320a1204df638176c3c2a88109fd1b27d9/deb/build/debian/jenkins.default#L75

/var/cache/jenkins will also be cleared on `apt-get purge jenkins`

AlbanAndrieu/Stouts.jenkins,TouqeerHussain/Stouts.jenkins,Seraf/Stouts.jenkins