Change plausible container data to regular volume

Bind mount caused issues, apparently permissions issue, I don't want to
debug it anymore.

compose.yml

@@ -44,7 +44,7 @@ services:
       plausible_events_db:
         condition: service_healthy
     volumes:
-      - ./data/plausible:/var/lib/plausible
+      - plausible-data:/var/lib/plausible
     ulimits:
       nofile:
         soft: 65535
@@ -88,3 +88,6 @@ services:
       - MAILGUN_BASE_URI
       - MANDRILL_API_KEY
       - SENDGRID_API_KEY
+
+volumes:
+  plausible-data: