ra: Pass the '--overwrite' flag to the 'kubectl label' command

Signed-off-by: Rémy Coutable <remy@rymai.me>

scripts/review_apps/review-apps.sh

@@ -166,8 +166,9 @@ function label_namespace() {
   local label="${2}"
 
   echoinfo "Labeling the ${namespace} namespace with ${label}" true
+  echoinfo "We should pass the --overwrite option!"
 
-  kubectl label namespace "${namespace}" "${label}"
+  kubectl label --overwrite namespace "${namespace}" "${label}"
 }
 
 function create_application_secret() {