icinga2x-cluster: Do not mount icingaweb2/config anymore

Configuration is located in /etc/icingaweb

https://git.icinga.org/?p=icingaweb2.git;a=commit;h=02007cf9fb9208c1b6238d59d59b85446321f3f1
icinga2x-cluster: Fix file permissions for vbox mount

https://git.icinga.org/?p=icingaweb2.git;a=commit;h=274fc58d0f9aed995610113681a9300213cfd5ae