project: Require git >= 1.7.2 for setting config on command line

This option causes the git call to fail, which probably indicates a
programming error; callers should check the git version and change the
call appropriately if -c is not available. Failing loudly is preferable
to failing silently in the general case.

For an example of correctly checking at the call site, see I8fd313dd.
If callers prefer to fail silently, they may set GIT_CONFIG_PARAMETERS
in the environment rather than using the config kwarg to pass
configuration.

Change-Id: I0de18153d44d3225cd3031e6ead54461430ed334
1 file changed