glx/dri2: Paper over errors in DRI2Connect when indirect

glx/dri2: Paper over errors in DRI2Connect when indirect

DRI2 will throw BadRequest for this when the client is not local, but
DRI2 is an implementation detail and not something callers should have
to know about.  Silently swallow errors in this case, and just propagate
the failure through DRI2Connect's return code.

Note: This is a candidate for the stable release branches.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=28125
Signed-off-by: Christopher James Halse Rogers <christopher.halse.rogers@canonical.com>