WFLY-3189 - Do not use schema location in schema element. Do not use
schemaLocation when importing a namespace.

XML validators seem to get confused when schema location is specified
and imports / includes are circular. Instead rely on entries in XML
catalogue.
WFLY-3189 - Remove element assembly-descriptor from complex type jboss-ejb-jarType since it is already defined in the parent type and adding it again is not allowed.