Add imaplib.IMAP4.abort to exception classes for retry_crispin.
Add imaplib.IMAP4.abort to exception classes for retry_crispin.

This is so that we can retry on imaplib.IMAP4.abort('socket error: EOF')
errors.

jobscore/sync-engine,EthanBlackburn/sync-engine,EthanBlackburn/sync-engine,PriviPK/privipk-sync-engine,jobscore/sync-engine,nylas/sync-engine,EthanBlackburn/sync-engine,Eagles2F/sync-engine,PriviPK/privipk-sync-engine,jobscore/sync-engine,rmasters/inbox,closeio/nylas,closeio/nylas,EthanBlackburn/sync-engine,nylas/sync-engine,gale320/sync-engine,rmasters/inbox,wakermahmud/sync-engine,gale320/sync-engine,gale320/sync-engine,gale320/sync-engine,Eagles2F/sync-engine,nylas/sync-engine,ErinCall/sync-engine,rmasters/inbox,ErinCall/sync-engine,gale320/sync-engine,PriviPK/privipk-sync-engine,jobscore/sync-engine,closeio/nylas,wakermahmud/sync-engine,wakermahmud/sync-engine,rmasters/inbox,ErinCall/sync-engine,PriviPK/privipk-sync-engine,ErinCall/sync-engine,closeio/nylas,wakermahmud/sync-engine,nylas/sync-engine,Eagles2F/sync-engine,Eagles2F/sync-engine,EthanBlackburn/sync-engine,PriviPK/privipk-sync-engine,Eagles2F/sync-engine,wakermahmud/sync-engine,ErinCall/sync-engine