Catch "collection truncated" errors from Mongo 3.2
Catch "collection truncated" errors from Mongo 3.2

Running the mongo/oplog_test.go tests that truncate the oplog capped
collection against Mongo 3.2 sometimes produces the following error
instead of mgo.ErrCursor:

&mgo.QueryError{Code:17406, Message:"getMore executor error: OperationFailed: Operation aborted because: collection truncated", Assertion:false}

bac/juju,mjs/juju,perrito666/juju,frankban/juju,reedobrien/juju,kat-co/juju,frankban/juju,howbazaar/juju,bz2/juju,anastasiamac/juju,anastasiamac/juju,mikemccracken/juju,axw/juju,waigani/juju,marcmolla/juju,macgreagoir/juju,frankban/juju,ericsnowcurrently/juju,howbazaar/juju,macgreagoir/juju,dimitern/juju,anastasiamac/juju,ericsnowcurrently/juju,ericsnowcurrently/juju,reedobrien/juju,AdamIsrael/juju,howbazaar/juju,gabriel-samfira/juju,alesstimec/juju,reedobrien/juju,AdamIsrael/juju,frankban/juju,mjs/juju,mjs/juju,kat-co/juju,bac/juju,kat-co/juju,AdamIsrael/juju,mjs/juju,alesstimec/juju,bz2/juju,reedobrien/juju,bac/juju,AdamIsrael/juju,dooferlad/juju,marcmolla/juju,waigani/juju,dooferlad/juju,dimitern/juju,macgreagoir/juju,ericsnowcurrently/juju,macgreagoir/juju,axw/juju,mikemccracken/juju,axw/juju,gabriel-samfira/juju,bz2/juju,anastasiamac/juju,dooferlad/juju,mjs/juju,bac/juju,axw/juju,mikemccracken/juju,kat-co/juju,alesstimec/juju,waigani/juju,ericsnowcurrently/juju,dimitern/juju,bz2/juju,howbazaar/juju,dimitern/juju,perrito666/juju,macgreagoir/juju,kat-co/juju,alesstimec/juju,howbazaar/juju,mikemccracken/juju,gabriel-samfira/juju,dooferlad/juju,anastasiamac/juju,bac/juju,mjs/juju,mikemccracken/juju,marcmolla/juju,alesstimec/juju,bz2/juju,marcmolla/juju,gabriel-samfira/juju,marcmolla/juju,frankban/juju,mjs/juju,perrito666/juju,reedobrien/juju,dimitern/juju,perrito666/juju,axw/juju,waigani/juju,dooferlad/juju,gabriel-samfira/juju,perrito666/juju