Old networks are never removed

[davidknezic]

Every time a connection is made to a new wifi network, it is appended to the wpa_supplicant.conf file. All previous connections persist and keep a higher priority.

We should always remove all previous connections when a new one is made.

It looks like we'll have to call wpa_cli list_networks to get all networks and then execute wpa_cli remove_network 0 for every entry, right before adding and saving a new network.

source: https://stackoverflow.com/a/43763119