Remove two sets that are not referenced

The code no longer references the updated_routers and removed_routers
sets.  This should have been cleaned up before but was missed.

Change-Id: I0396e13d2f7c3789928e0c6a4c0a071b02d5ff17
Remove all_routers argument from _process_routers

There is no code left that passes True to this argument.  It is dead
code and it should be removed.

Change-Id: I55f71a5c0b96e530e45f2a6463978e8611cbc537
Merge "Remove all_routers argument from _process_routers"
Merge "Remove two sets that are not referenced"