git-gui: Show/hide "Sign Off" based on nocommitmsg option

If citool --nocommit is invoked we hide the Sign Off features, as
the commit message area is not editable.  But we really want the
selection tied to the message area's editing ability.

Suggested-by: Alexander Gavrilov <angavrilov@gmail.com>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
1 file changed