Flannel: fix init container image arch (#9461)

The install-cni-plugin image was not updated to the corresponding
arch when building the different DS.

Fixes issue #9460

Signed-off-by: Fred Rolland <frolland@nvidia.com>

Signed-off-by: Fred Rolland <frolland@nvidia.com>

roles/network_plugin/flannel/templates/cni-flannel.yml.j2

@@ -114,7 +114,7 @@ spec:
                       - {{ arch }}
       initContainers:
       - name: install-cni-plugin
-        image: {{ flannel_init_image_repo }}:{{ flannel_init_image_tag }}
+        image: {{ flannel_init_image_repo }}:{{ flannel_init_image_tag | regex_replace(image_arch,'') }}{{ arch }}
         command:
         - cp
         args: