Stop running services if the user wants to change provider.

**DO NOT MERGE**

If the user changes the selected provider, we ask if he wants to stop the running servers since is needed to do the change.

Right now there is a problem that when the services are stopped, the EIP widget seems to have the firewall up (has two buttons)... working on it.
Why ask whether we should block signals if you *are* blocking them? I would change this comment to explaining why we block signals bellow