`Converter.parse_line` doesn't remove remove trailing whitespace before comments
For example:
Converter.parse_line(" stub-addr: 193.0.14.129 # K.ROOT-SERVERS.NET.
)`
leads to:
Converter._check_ipaddress("193.0.14.129 ")
which fails for obvious reasons.
In general, it is really hard to work with all the regexes and corner cases of parsing a configuration file with parser written from scratch. I dare to guess the most of real-life unbound.conf
files would not pass converter.py
in the current state.