[tunnelbroker] Ignore CONNECTIONFORCED error message

Summary:
ENG-9593.
Yet another message for the same error cause. Added to ingored

Test Plan: Similiar to D13608 but this time gracefully shutdown RabbitMQ - it sends the CONNECTIONFORCED message then

Reviewers: kamil, will, varun

Reviewed By: kamil

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D13703