packaging: remove missing file from .spec

c9ef45ae removed the yum repo file
in order to not install the repo with the ring-daemon package, however
this file was till being referred to in another place causing the
packaging to fail

Change-Id: I6bf98122de6efb05af82b0fc50d56b2ca70fb547
Tuleap: #591

ring-daemon.spec

@@ -73,7 +73,6 @@ make DESTDIR=%{buildroot} install
 %{_datadir}/dbus-1/services/*
 %{_datadir}/dbus-1/interfaces/*
 %doc %{_mandir}/man1/dring*
-%config %{_sysconfdir}/yum.repos.d/ring-nightly.repo
 
 %files devel
 %defattr(-,root,root,-)