[Etherpad] Increase CPU limit to 0.40

This change was already in prod since some days, but not commited

pica-etherpad/docker-compose.yml

@@ -45,7 +45,7 @@ services:
     security_opt:
       - no-new-privileges
     mem_limit: "2048m"
-    cpus: "0.20"
+    cpus: "0.40"
     pids_limit: 1024
     volumes:
       - etherpad-db-volume:/var/lib/mysql