Do not install geoipupdate unless geoip_account_id is defined

This should make it possible to set up an environment successfully without setting up geoipupdate.

roles/float-util-geoip-base/tasks/main.yml

@@ -4,5 +4,6 @@
   apt:
     name: geoipupdate
     state: present
+  when: geoip_account_id is defined