Do not use pidfile in varnishncsa.service

This will make the service work out of the box by a simple
``systemctl enable varnishncsa``, as using the pidfile requires
``/var/run/varnishncsa`` to be created.

This is in line with the ``varnish.service`` anyway.

debian/varnishncsa.service

@@ -5,10 +5,9 @@ After=varnish.service
 [Service]
 RuntimeDirectory=varnishncsa
 Type=forking
-PIDFile=/run/varnishncsa/varnishncsa.pid
 User=varnishlog
 Group=varnish
-ExecStart=/usr/bin/varnishncsa -a -w /var/log/varnish/varnishncsa.log -D -P /run/varnishncsa/varnishncsa.pid
+ExecStart=/usr/bin/varnishncsa -a -w /var/log/varnish/varnishncsa.log -D
 ExecReload=/bin/kill -HUP $MAINPID
 
 [Install]