fixed bug in which undef was being returned from rearrange when zero should...

fixed bug in which undef was being returned from rearrange when zero should have been returned instead

modules/Bio/EnsEMBL/Utils/Argument.pm

@@ -131,7 +131,7 @@ sub rearrange {
   # What we intend to do is loop through the @{$order} variable,
   # and for each value, we use that as a key into our associative
   # array, pushing the value at that key onto our return array.
-  return map {$param{uc("-$_")} || $param{uc($_)}} @$order;
+  return map {$param{uc("-$_")}} @$order;
 }
 
 1;