cli: Warn if --rev flag is used with cilium service update
cli: Warn if --rev flag is used with cilium service update

Instead of returning an error, warn a user that the flag is deprecated
and inactive. This will prevent from breaking user scripts which used
to set the param.

Reported-by: Jarno Rajahalme
Fixes: 4234ed773 ("cli: Remove --rev param of cilium service update")
Signed-off-by: Martynas Pumputis <6b0d31c0d563223024da45691584643ac78c96e8@lambda.lt>

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