No-op for Salmons without body, fail fast if Webfinger does not contain

all required resource links (profile page, salmon, atom feed, magic key)

app/controllers/api/salmon_controller.rb

@@ -3,8 +3,14 @@ class Api::SalmonController < ApiController
   respond_to :txt
 
   def update
-    ProcessInteractionService.new.call(request.body.read, @account)
-    head 201
+    body = request.body.read
+
+    if body.nil?
+      head 200
+    else
+      ProcessInteractionService.new.call(body, @account)
+      head 201
+    end
   end
 
   private