Related to bug #1047111

That bug fixed the XXE attack by setting the following to true
 libxml_disable_entity_loader

This caused issues with the leap2a importer used by mnet, which
used the simplexml_load to load the xml which relies on file
based remote entities. For this situation, a the following flag
is used, which stops network based XXE attacks
 LIBXML_NONET

Change-Id: I3d95ebc9c38374d339d66a80feaa39f5c15f1022
Signed-off-by: Hugh Davenport <hugh@catalyst.net.nz>