Set default "" to extra runtime handler.

Random-Liu · estesp · commit 8162149479ee · 2020-10-01T16:51:41.000-04:00
Signed-off-by: Lantao Liu &lt;lantaol@google.com&gt;
diff --git a/contrib/gce/configure.sh b/contrib/gce/configure.sh
@@ -181,6 +181,8 @@ disabled_plugins = ["restart"]
 EOF
 chmod 644 "${config_path}"
 
+# CONTAINERD_EXTRA_RUNTIME_HANDLER is the extra runtime handler to install.
+CONTAINERD_EXTRA_RUNTIME_HANDLER=${CONTAINERD_EXTRA_RUNTIME_HANDLER:-""}
 if [[ -n "${CONTAINERD_EXTRA_RUNTIME_HANDLER}" ]]; then
   cat >> ${config_path} <<EOF
 [plugins.cri.containerd.runtimes.${CONTAINERD_EXTRA_RUNTIME_HANDLER}]
