Fix issue with cross-account ami sharing not working when no account is specified.
Fix issue with cross-account ami sharing not working when no account is specified.

MarkRose/buri,MarkRose/buri,viafoura/buri,inve1/buri,jhohertz/buri,viafoura/buri,inve1/buri,MarkRose/buri,jhohertz/buri,viafoura/buri,jhohertz/buri,jhohertz/buri,MarkRose/buri,viafoura/buri,inve1/buri,inve1/buri