This should be post-PuP but I don't know the label for it.

SERVER-133844 fixes a segfault from BF-45804 where truncateByMarkerQueue is doing a truncate at the same time the oplog cap maintainer thread's shutdown path is clearing the truncate markers. 

The fix was to do a null check on the markers and throw from truncateByMarkerQueue if they are null (better than the segfault).

This ticket is to investigate if there is a more graceful way to exit and to implement the graceful way to exit, like maybe we could replace the opCtx->checkForInterrupt() with checkForInterruptNoAssert so we don't throw an exception at all.