pkg/kamailio/centos/6: Updated Boxgrinder build appliance to install redhat-rpm-config

- This is needed to get debuginfo RPMs to build automatically

pkg/kamailio/centos/6/kamailio-build.appl

@@ -11,6 +11,7 @@ hardware:
       size: 4
 packages:
   - @core
+  - redhat-rpm-config		# kamailio-debuginfo
   - bison			# kamailio
   - db4-devel			# kamailio-bdb
   - expat-devel			# kamailio-xmpp