src/conf.py: disable strictRFC by default

strictRFC causes issues when nicks start with numbers and on some
network this happens too often. For example, if nick isn't RFC-compliant,
the bot cannot be used to kick user from channel. Ops cannot change this
so they must op themselves and kick the user by themselves or whatever
they are going to do.

Some IRCds also allow you to change your nick to your UID using `/nick
0` and on others it happens when there is nick collision after netsplit.