BuildRequires: s/postgresql-devel/libpq-devel/
    
    That's because we moved libpq.so.5 into libpq package.  But I had
    to add postgresql-server-devel too, even though it shouldn't be
    needed.  My guess is that the buildsystem configuration tooling
    mistakenly checks for server-related headers.
    
    Related: rhbz#1618698, rhbz#1623764