More than one network mount can be set to Use as HDD replacement

[prl]

There is no interlocking between mount edit screens to prevent more than one network mount being enabled as Use as HDD replacement.

The mount processing in NetworkBrowser is in order of the entries in a dict, so the results of setting more than one mountpoint to be Use as HDD replacement depends on both the order of iteration over the dict and the Mount type settings on the mounts with Use as HDD enabled.

Replication

Create more than one network mount, mark more than one as Use as HDD replacement (rebooting if necessary when that is done to work around issue #740). Note that doing it is possible in the first place, and the unpredictable result.