add missing if

Author: spowelljr

deploy/addons/gvisor/gvisor-runtimeclass.yaml.tmpl

@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-apiVersion: node.k8s.io/v1{{.LegacyRuntimeClass}}beta1{{end}}
+apiVersion: node.k8s.io/v1{{if .LegacyRuntimeClass}}beta1{{end}}
 kind: RuntimeClass
 metadata:
   name: gvisor