Add history section for bsdlabel(8)
http://minnie.tuhs.org/cgi-bin/utree.pl?file=4.3BSD-Tahoe/usr/man/cat8/disklabel.0
Remove tab after space, highlighted by igor

PR: 212436
Approved by: bcr (mentor)
MFC after: 5 days
Differential Revision: https://reviews.freebsd.org/D8104