setup-interfaces: find essids when UTF-8 SSID capability present
When a essid has the 'UTF-8 SSID' extended capibility, the find_essids
function will not return that ssid. This bug is very similar to the one
fixed in commit 6c9955ef, and solved by ensuring nothing but whitespace
precedes the matched key in the regex.
Partial output of iw dev wlan0 scan
:
Extended capabilities:
* Extended Channel Switching
* UTF-8 SSID
* Operating Mode Notification