If oe-git-proxy-socks isn't available, try and create it.
If that fails, tell the user there is a problem, don't just fail
to find the command.
[YOCTO #2007]
(From OE-Core rev: 46c675d85603d7a573bc59638ce615aba9fd7df2)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>