Return None when author is deleted.
Return None when author is deleted.

praw-dev/praw,gschizas/praw,praw-dev/praw,iAmMrinal0/reddit,voussoir/reddit,tehp/reddit,13steinj/praw,RGood/praw,nmtake/praw,darthkedrik/praw,RGood/praw,tehp/reddit,TacticalGoat/reddit,TacticalGoat/reddit,tehp/reddit,darthkedrik/praw,nmtake/praw,voussoir/reddit,13steinj/praw,gschizas/praw,leviroth/praw,leviroth/praw,iAmMrinal0/reddit