Fix table in generated plugins list

Fix the table with a bottom border.  Regenerate the plugin list using
the script to make sure it works this time.

Change-Id: Iab3eb3879fd6017c55259e470477e4a9e34514e2
diff --git a/tools/generate-devstack-plugins-list.sh b/tools/generate-devstack-plugins-list.sh
index ea30cd5..95f1331 100644
--- a/tools/generate-devstack-plugins-list.sh
+++ b/tools/generate-devstack-plugins-list.sh
@@ -78,6 +78,9 @@
     gitlink="https://git.openstack.org/cgit/openstack/${plugin}"
     printf "%-${name_col_len}s %s\n" "${plugin}" "\`${giturl} <${gitlink}>\`__"
 done
+
+title_underline ${name_col_len}
+
 printf "\n\n"
 
 if [[ -r data/devstack-plugins-registry.footer ]]; then