make better condition for applying nf_conntrack kernel tweak (#6267)

* MINOR: Check kernel version before enable modprobe nf_conntrack

* CLEANUP: no more need to ignore error of this task

* MINOR: Fixing yaml and ansible lint error - remove trailling-space

roles/kubernetes/node/tasks/main.yml

@@ -108,8 +108,9 @@
     name: nf_conntrack_ipv4
     state: present
   register: enable_nf_conntrack
-  ignore_errors: yes
-  when: kube_proxy_mode == 'ipvs'
+  when:
+    - ansible_kernel.split('.')[0:3] | join('.')  < '4.19'
+    - kube_proxy_mode == 'ipvs'
   tags:
     - kube-proxy
 
@@ -118,7 +119,7 @@
     name: nf_conntrack
     state: present
   when:
-    - enable_nf_conntrack is failed
+    - ansible_kernel.split('.')[0:3] | join('.')  >= '4.19'
     - kube_proxy_mode == 'ipvs'
   tags:
     - kube-proxy