[contrail-vrouter] Fix recommends package

kernel-image-$(uname -r) doesn't exist, the correct package name is
linux-image-$(uname -r).

Change-Id: I9bcdcf88f1c545a6cba0ee557c6f9c3b2646e194
(cherry picked from commit 7cf0871cdf0cf0ae3e79e878650be23f62508d04)
Merge "[contrail-vrouter] Fix recommends package" into R1.06