net-mgmt/icingaweb2: fix problems running the application

Icingaweb failed with stack traces when being accessed due to missing
php module dependencies:

mime_content_type requires fileinfo.
Cron\filter_var requires filter.

Also, icingaweb fails at access, missing Locale class, if built without
the NLS option. Remove the NLS options, since it seems broken.

PR: 271662