Description of problem:
the pgtune assumes the postgresql-server has to be installed.  This conflicts with running software collections of postgres

Version-Release number of selected component (if applicable):
0.9.3

How reproducible:
enable software collections for system
install software collections version of postgres
install pgtune

Steps to Reproduce:
1. 
2.
3.

Actual results:
`yum install pgtune` attempts to install `postgresql-server`

Expected results:
`yum install pgtune` should not attempt to install `postgresql-server`.  pgtune should just fail if it cannot find the postgresql.conf in the default expected location and in that case should expect --input-config= arg

Additional info:
pgtune runs fine with scl version of postgresql server; it may require that the postgres binaries' paths are added to the default env paths and that the main system ldconf includes the scl variant libs in its search path.