/etc/apache2/conf-available/icinga-web.conf is in icinga-web 1.11.2+dfsg1-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /etc/apache2/conf-available/../../icinga-web/apache2.conf
/etc/apache2/conf-available/../../icinga-web/apache2.conf