Fixed #114 -- Removed default owner for tickets

The previous configuration would display a "< default >" user
as a value in the dropdown on ticket creation, and using that
value would then assign the ticket to the component's owner.
But we don't use component owners, so the result was that the
ticket was assigned to an empty string.

trac-env/conf/trac.ini

@@ -195,6 +195,7 @@ authz_module_name =
 [ticket]
 default_component = Uncategorized
 default_milestone = 
+default_owner =
 default_priority = major
 default_type = bug / defect
 default_version = 5.0