Fixes #551: avoid a deadlock in retrieveAndAddAccountsByAccess;
Fixes #551: avoid a deadlock in retrieveAndAddAccountsByAccess;

The function was wrapped to be executed in the sequential queue; however, since
it's just calling retrieveNewAccountsByAccess, which is also wrapped, and the
sequential queue is not re-entrant by definition, it was causing a deadlock.
Not wrapping the function is enough, since the callee is still wrapped and
executed in a sequential fashion.

bnjbvr/kresus,ZeHiro/kresus,bnjbvr/kresus,bnjbvr/kresus,bnjbvr/kresus,jankeromnes/kresus,jankeromnes/kresus,jankeromnes/kresus,ZeHiro/kresus,ZeHiro/kresus,jankeromnes/kresus,ZeHiro/kresus