Fixed errcheck issues in server/channels/app/security_update_check.go (#29200)

server/.golangci.yml

@@ -104,7 +104,6 @@ issues:
         channels/app/plugin_test.go|\
         channels/app/post_helpers_test.go|\
         channels/app/post_test.go|\
-        channels/app/security_update_check.go|\
         channels/app/server.go|\
         channels/app/slack.go|\
         channels/app/slashcommands/auto_environment.go|\