restapi: Use correct parameters for network removal

Parameters class for removing network was changed but not in REST API
usage, so fixed to use correct parameters class.

Change-Id: Ibf77dbf2a9027d5310d74fc9bceaad6e7d768ef2
Bug-Url: https://bugzilla.redhat.com/1051867
Signed-off-by: Mike Kolesnik <mkolesni@redhat.com>