webadmin: policy: fields reset when changing options

Problem: When changing the cluster policy properties (filters/weight/balance)
the custom properties sheet was reset.

Solution: refresh the custom propeties sheet inculding the
values that already set.

Change-Id: Ibb3092953f3ff387625cf00c146f63ea41f58de2
Bug-Url: https://bugzilla.redhat.com/1002171
Signed-off-by: Gilad Chaplik <gchaplik@redhat.com>