modify data-port reports error of bridge/port already excisting

[Fairbanks.]

Hello,

When i want to modify the data-port value via juju config (or juju set) it sometimes fails.
It happens when for instance you only change the physical interface part of br-ex.
Then it complains that br-ex already exists, i first have to remove the config from the charm, and later add it again, this works.

I think the charm first should look if it already exists, and if it does, if it already is linked to the correct interface, if not, then remove the port and add it again pointing to the correct physical interface.

Thx :).

[James Page (james-page)]

This codepath could be improved a bit.