playbook: Prompt for re6st config with defaults

As vars_files has higher precedence than vars_prompt, remove
re6st_registry_url and re6st_fingerprint from settings/vifib.yml.

playbook/re6stnet.yml

@@ -14,6 +14,16 @@
       private: no
       default: "noname"
 
+    - name: "re6st_registry_url"
+      prompt: "What is the url to the Re6st registry?"
+      private: no
+      default: "http://re6stnet.nexedi.com/"
+
+    - name: "re6st_fingerprint"
+      prompt: "What is the Registry fingerprint?"
+      private: no
+      default: "sha256:61a8f3ef4bdf12aca0dad5c17e8fadd15966bdd68b1400c91ef8ee53f17c0d65"
+
   roles:
     - { role: re6stnet, package_state: present }
 

playbook/settings/vifib.yml

 ---
 re6st_registry_url: http://re6stnet.nexedi.com/
 re6st_fingerprint: sha256:61a8f3ef4bdf12aca0dad5c17e8fadd15966bdd68b1400c91ef8ee53f17c0d65
+slapos_master_url: https://slap.vifib.com/
+slapos_web_master_url: https://slapos.vifib.com/
 interface_name: lo
 re6st_annon: True
 re6sttoken: noname