devel/distcc: update to 3.3.3

Update to 3.3.2 in r475448 was wrong because GH_TAGNAME was not updated
accordingly.

This was spotted by ngie@ who provided the first version to move to 3.3.3

See https://github.com/distcc/distcc/releases for changes from 3.1 to 3.3.3

Submitted by: ngie@
Reported by: ngie@
Reviewed by: 0mp, fernape@, mat@
Approved by: 0mp
Differential Revision: https://reviews.freebsd.org/D21259