In load_registry_from_multiple_dbs(): Initialize the hash with () rather

than {}.

modules/Bio/EnsEMBL/Registry.pm

@@ -2122,7 +2122,7 @@ sub load_registry_from_multiple_dbs {
   my %merged_register = %registry_register;
 
   foreach my $arg (@args) {
-    local %registry_register={};
+    local %registry_register = ();
 
     my $verbose;