Support git receive-pack as well as git-receive-pack when pushing Git over SSH (BB-7499)

The default git configuration for some users on Ubuntu and other recent versions of Git will have the following in their Git configuration:

#!bash

remote.origin.receivepack=git receive-pack

Bitbucket's Git/SSH server only accepts:

#!bash

remote.origin.receivepack=git-receive-pack

This should be changed on the Bitbucket side.