Add guard for nil in our RateLimiter.

spec/components/rate_limiter_spec.rb

@@ -96,7 +96,7 @@ describe RateLimiter do
     context 'max is less than or equal to zero' do
 
       it 'should raise the right error' do
-        [-1, 0].each do |max|
+        [-1, 0, nil].each do |max|
           expect do
             RateLimiter.new(user, "a", max, 60).performed!
           end.to raise_error(RateLimiter::LimitExceeded)