fix callback in the not_log_message assertion so it reports the failu…

…re correctly

spec/spec_helper/matchers/not_log_message.rb

@@ -6,7 +6,8 @@
   match notify_expectation_failures: true do |actual|
     with_memory_logger expected.to_h[:using_log_level] do |logger|
       actual.call
-      logger ? logger.empty? : true
+      (expect logger).to be_empty if logger
+      true
     end
   end