[vi] remove unused repo gpgkey for yum repo

Author: Arhell

content/vi/docs/tasks/tools/install-kubectl.md

@@ -73,7 +73,7 @@ baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64
 enabled=1
 gpgcheck=1
 repo_gpgcheck=1
-gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
+gpgkey=https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
 EOF
 yum install -y kubectl
 {{< /tab >}}