The nova debuger functionality was intended
to help debugging running process however it has
never been reliable due to our use of eventlet and is generally
not required when not using eventlet. I.e. you can just
run the nova console-scripts form a debugger or add pdb
statements as required.
As part of the eventlet removal the debugger functionality is
removed given its untested and undocumented.
Change-Id: I7bf88f06f3d1dbd2c7e342b27a21440a123c631d