[git-buildpackage] Fixes to allow package to build on centos7 and centos8

[Quanah Gibson-Mount]

I've opened a pull request on github with the changes that allowed me to 
build an RPM for both centos7 and centos8 without any errors:

<https://github.com/agx/git-buildpackage/pull/81>

Regards,
Quanah

--

Quanah Gibson-Mount
Product Architect
Symas Corporation
Packaged, certified, and supported LDAP solutions powered by OpenLDAP:
<http://www.symas.com>