[git-buildpackage] Fix for using current mock

[Quanah Gibson-Mount]

I fixed up gbp-builder-mock to work with current mock releases.  Patch 
attached.

Regards,
Quanah

--

Quanah Gibson-Mount
Product Architect
Symas Corporation
Packaged, certified, and supported LDAP solutions powered by OpenLDAP:
<http://www.symas.com>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0001-Update-gbp-builder-mock-to-work-with-current-mock-re.patch.gz
Type: application/x-gzip
Size: 724 bytes
Desc: not available
URL: <http://lists.sigxcpu.org/pipermail/git-buildpackage/attachments/20210503/c0924c89/attachment.bin>