Make Pvs_proxy_control.stop_proxy independent of currently_attached
Make Pvs_proxy_control.stop_proxy independent of currently_attached

This doesn't work, because currently_attached become `false` too early, when
the OVS rules are removed. It's also unnecessary, because the function is
idempotent.

Signed-off-by: Rob Hoes <8783b3376fb07d39edffc8d7da68a6de3874a7e6@citrix.com>

thomassa/xen-api,srowe/xen-api,srowe/xen-api,Frezzle/xen-api,Frezzle/xen-api,srowe/xen-api,thomassa/xen-api,thomassa/xen-api,euanh/xen-api,thomassa/xen-api,srowe/xen-api,Frezzle/xen-api,euanh/xen-api,Frezzle/xen-api,euanh/xen-api,thomassa/xen-api,euanh/xen-api,euanh/xen-api,srowe/xen-api,Frezzle/xen-api,euanh/xen-api,thomassa/xen-api