Missing dependency on the rrdtool RPM installed through yum.postgresql.org

The YUM Repository for 17 Snapshot, has a package for RRDtool:

http://yum.opennms.org/snapshot/rhel7/opennms/x64/rrdtool-1.5.3-0.3.el7.centos.x86_64.rpm

On a clean installation on CentOS 7 x86_64, the graphs are not rendered due to an issue with the Pango library.

After installing the following package, the problem is gone:

dejavu-sans-fonts

I think it is a good idea to make our rrdtool package depends on that library to be sure that it will work.