switched to new Registry system where DBAdaptor hold connection rather than

inherit from them (as in $dba->dbc->)

modules/Bio/EnsEMBL/Hive/Worker.pm

@@ -281,7 +281,7 @@ sub run
   }
   $self->print_worker();
 
-  $self->db->disconnect_when_inactive(1);
+  $self->db->dbc->disconnect_when_inactive(1);
 
   my $jobDBA = $self->db->get_AnalysisJobAdaptor;
   my $alive=1;