Bug 974867 - [MMS]Auto suggestion for email address r=Julien

https://bugzilla.mozilla.org/show_bug.cgi?id=974867
This doesn't work properly when supportEmailRecipient is false: in that case, we don't return when we have no tel.

Please use this instead:
```javascript
var hasTel = contact.tel && contact.tel.length;
var hasEmail = contact.email && contact.email.length;
if (!hasTel && !(Settings.supportEmailRecipient && hasEmail)) {
  return false;
}
```

Please add a unit test for this case.