use request uri and regex to choose callbacks

scripts/webfinger_allowlist.lua

@@ -6,6 +6,11 @@ function webfingerCallback(cfg)
 
     local resource = args['resource']
     if resource ~= nil then
+      -- TODO this is O(n) but we can make it O(1) by doing a funny and making
+      -- cfg.accounts be transformed into keys in a table
+      --
+      -- this would require us to do some setup() callback as well as
+      -- the request() callback
       for _, account in ipairs(cfg.accounts) do
         if resource == account then
           return true
@@ -27,7 +32,6 @@ return {
     Useful for small instances.
     ]],
     apiVersion=1,
-    callback=webfingerCallback,
     callbacks = {
         ['/.well-known/webfinger'] = webfingerCallback
     },