Fail at setting Tor bridge mode when using Unsafe Browser to get bridges

Originally created by @Anonymous on #11535 (Redmine)

how does it happen:

start tails > more > need bridge > login > connect ethernet > tor configuration pop up > open unsafe browser > visit https://bridges.torproject.org > copy bridge data

then:

1: if unsafe browser is closed and bridges are pasted into tor setup configuration after closing unsafe browser > error as in subject

2: if unsafe browser is kept open and bridges are pasted > proceed connecting > then close unsafe browser > NO ERROR

Related issues

• Related to #8825 (closed)
• Related to #15331 (closed)