Upgrade Etherpad role (v1.8.18-1 -> v1.8.18-2)

requirements.yml

@@ -49,7 +49,7 @@
   version: v7.0.9-0
 
 - src: git+https://gitlab.com/etke.cc/roles/etherpad.git
-  version: v1.8.18-1
+  version: v1.8.18-2
 
 - src: git+https://github.com/devture/com.devture.ansible.role.traefik.git
   version: 4ec9187017cb7832f521fc273fabd0a873ca2736