lib/oe/patch: GitApplyTree: save 1 echo in commit-msg hook
* also remove the extra blank lines which is often added to patches
when refreshed with devtool (GitApplyTree.patch_line_prefix lines
are ignored when refreshing .patch files, but newly added blank
lines aren't - the leading blank line wasneeded for patches with
just the subject line (to prevent the GitApplyTree.patch_line_prefix
line ending appended to the commit summary), but we can add it
in prepareCommit instead
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org> Signed-off-by: Steve Sakoman <steve@sakoman.com>
