test(functional): Don't use a dead test server

It appears that when running in the gate, the wsgiref server sometimes
goes away. This adds a check to only reuse a server instance if it
is still alive.

Change-Id: I87716f9feb80da63a6b8c1f629178b396dbeb4c6
chore: Fix pylint errors

Fixed a couple pylint errors and disabled remaining false positives.

Change-Id: Ib7e6f42e98f31af1c731c0b69fd26de1572b4471