networking.7: remove confusing caveat

+ service routing restart breaks on dhcp
+ change my copyright from inbox to home

Fixes: 75eda009
MFC after: 3 days
Reported by: Graham Perrin, zlei
Reviewed by: imp
Pull Request: https://github.com/freebsd/freebsd-src/pull/1316

(cherry picked from commit c55f56de9da11e11ee950993afe8b8575d8daa56)