Remove code prefixing "httproute-" in targetRefs.name field of securitypolicy ref.

[haahaakon]

The securitypolicy does not match the HTTPRoute when the prefix "httproute-" is in the name field of the ref.

Example

k get httproute
NAME                      HOSTNAMES                                    AGE
my-nginx-hnet-httproute   ["fredag.t-lb-001.central-az1.sky.nhn.no"]   10m

results in this ref:

  targetRefs:
  - group: gateway.networking.k8s.io
    kind: HTTPRoute
    name: httproute-my-nginx-hnet-httproute

which will not match the actual httproute. This fix aims to correct that.