CLOUDSTACK-7563: Fix potential NPE in checking answer

Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>
(cherry picked from commit d42e3df9cf43b0ad46d406c6ab5b1d8c811d0239)
Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>