Bug 6540 - Followup - koha-create would die without --configfile

Bug 6540 - Followup - koha-create would die without --configfile

koha-create would fail to check that --configfile was set on the
commandline, before either including it if it existed or dying if
it did not. This patch should make sure the existence of a
configfile is only tested if --config is set.

Signed-off-by: Robin Sheat <robin@catalyst.net.nz>
This should apply against 3.4 and master.
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>
(cherry picked from commit 31bb901e2b31748dd86e7da45672c42a5359c5a4)

Signed-off-by: Chris Nighswonger <chris.nighswonger@gmail.com>