engine: adding no-arg constructor to RemoveVdsParameters

According to GWT serialization policy the classes used
in serialization should have a no-arg constructor.
Added a no-arg constructor to RemoveVdsParameters class

Change-Id: Ice662caf5e6a96858cf9d1f788cbf4b4744dcf7a
Bug-Url: https://bugzilla.redhat.com/1012826
Signed-off-by: Kanagaraj M <kmayilsa@redhat.com>