create-pull-request: don't switch the git remote protocol to git://

create-pull-request: don't switch the git remote protocol to git://

Many git repos prefer https:// nowadays and many removed support
for git://.

This breaks the script when using github.com even when selected remote
is ssh (git@github.com:openembedded/...), it will re-write it to git://
before calling git pull-request causing:

openembedded-core $ scripts/create-pull-request -u github -b jansa/artifacts -o pull-kernel
NOTE: Assuming local branch HEAD, use -l to override.
fatal: unable to connect to github.com:
github.com[0: 140.82.121.3]: errno=Connection timed out

warn: No match for commit ea003bd026aa24bb4c8b7562f44ed6512e921259 found at git://github.com/shr-distribution/oe-core
warn: Are you sure you pushed 'jansa/artifacts' there?
ERROR: git request-pull reported an error

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit 64c466920b808c35d1ac87b47cf438bc79becea7)
Signed-off-by: Steve Sakoman <steve@sakoman.com>