DEV: Fix randomly failing spec.

If a user is created with an id of 999, a `upload.user_id ==
user_avatar.user_id` will return true. This fix increases the id of the
upload to something that we will not hit in the foreseeable future.

spec/components/guardian/user_guardian_spec.rb

@@ -25,13 +25,13 @@ describe UserGuardian do
   end
 
   let :already_uploaded do
-    u = Upload.new(user_id: 999, id: 2)
+    u = Upload.new(user_id: 9999, id: 2)
     user_avatar.custom_upload_id = u.id
     u
   end
 
   let :not_my_upload do
-    Upload.new(user_id: 999, id: 3)
+    Upload.new(user_id: 9999, id: 3)
   end
 
   let(:moderator_upload) do