pkg/proxy: use u8proto values in proxymap lookups
pkg/proxy: use u8proto values in proxymap lookups

u8Proto specifies the wire-format values for us, and we can avoid the
hard-coded numbers.

Signed-off-by: Ray Bejjani <7f525154e857f3d57a641a83dddc584f42addc6a@covalent.io>

tgraf/cilium,cilium/cilium,scanf/cilium,scanf/cilium,tgraf/cilium,michi-covalent/cilium,tklauser/cilium,cilium/cilium,cilium/cilium,scanf/cilium,cilium/cilium,scanf/cilium,tgraf/cilium,michi-covalent/cilium,tklauser/cilium,tklauser/cilium,scanf/cilium,michi-covalent/cilium,michi-covalent/cilium,tgraf/cilium,scanf/cilium,tgraf/cilium,scanf/cilium,cilium/cilium,tgraf/cilium,michi-covalent/cilium,cilium-team/cilium,tklauser/cilium,tklauser/cilium,cilium-team/cilium