Retire noisebridge01 default bridge
Our default bridge noisebridge01 has been running smoothly for years but it's now unmaintained. I contacted each of its former operators repeatedly. Some didn't respond and the ones that did were unable to point me to a new contact. We should therefore remove noisebridge01 from our default bridges. It can still be useful as an ordinary bridge. By removing noisebridge01, we will finally be able to close legacy/trac#13727 (moved). I'll push patches for this in a jiffy.