UniqueHost: Fix incorrect identification of conflicting route

When a route is rejected due to the host already being claimed, the
incorrect route was being identified as the conflicting one. The
problem was that the first route in the array was always being
returned as the conflicting route, instead of the actual conflicting
one.

This fix addresses the issue by returning the last route in the slice,
which corresponds to the correct conflicting route. This ensures that
the "HostAlreadyClaimed" error properly identifies the correct
conflicting route, taking into account both host and path.

Fixes: https://issues.redhat.com/browse/OCPBUGS-16707

pkg/router/controller/unique_host.go

@@ -179,7 +179,7 @@ func (p *UniqueHost) HandleRoute(eventType watch.EventType, route *routev1.Route
 			// we were not added because another route is covering us
 			var owner *routev1.Route
 			if old, ok := p.index.RoutesForHost(host); ok && len(old) > 0 {
-				owner = old[0]
+				owner = old[len(old)-1]
 			} else {
 				owner = &routev1.Route{}
 				owner.Name = "<unknown>"