bitbake: bitbake:hob: use a socks proxy mechanism for git

bitbake: bitbake:hob: use a socks proxy mechanism for git

Instead of a custom git proxy mechanism, Hob now
uses a SOCKS proxy in order to work with external
repos via the oe-git-proxy helper script.

Fixes [YOCTO #4187]

(Bitbake rev: 0b81a2c4a5611b64dbdd40131730a82c149b94a2)

Signed-off-by: Cristian Iorga <cristian.iorga@intel.com>
Signed-off-by: Cristian Iorga <ubik3000@gmail.com>
Signed-off-by: Cristian Iorga <cristian.iorga@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>