.travis:fix test failed caused by timeout
.travis:fix test failed caused by timeout

Add waiting time to process kvstore.EventTypeDelete

Signed-off-by: Jianlin Lv <752eae91a476c3d35f9a7fd15fcd40979a048de4@arm.com>

tgraf/cilium,michi-covalent/cilium,cilium/cilium,tgraf/cilium,tklauser/cilium,cilium/cilium,tklauser/cilium,michi-covalent/cilium,tgraf/cilium,cilium/cilium,cilium-team/cilium,tklauser/cilium,tklauser/cilium,tgraf/cilium,michi-covalent/cilium,michi-covalent/cilium,michi-covalent/cilium,cilium-team/cilium,tgraf/cilium,tklauser/cilium,cilium/cilium,cilium/cilium,tgraf/cilium