multimedia/aegisub: mark BROKEN

In file included from /wrkdirs/usr/ports/multimedia/aegisub/work/aegisub-3.2.2/libaegisub/include/libaegisub/mru.h:16:
In file included from /usr/local/include/boost/filesystem/path.hpp:21:
/usr/local/include/boost/filesystem/detail/path_traits.hpp:495:16: error: call to '_check_convertible_to_path_source' is ambiguous

sizeof(is_convertible_to_path_source< T >::_check_convertible_to_path_source(boost::declval< T const& >())) == sizeof(yes_type);

Reported by: pkg-fallout