CI: fix check for kube_version

tests/testcases/010_check-apiserver.yml

@@ -12,6 +12,5 @@
 - name: Check API servers version
   assert:
     that:
-    - apiserver_response.json.gitVersion == kube_version
-    fail_msg: "apiserver version different than expected {{ kube_version }}"
-  when: kube_version is defined
+    - apiserver_response.json.gitVersion == ('v' + kube_version)
+    fail_msg: "apiserver is {{ apiserver_response.json.gitVersion }}, expected {{ kube_version }}"