Fix incorrect word.

activesupport/lib/active_support/log_subscriber/test_helper.rb

@@ -27,7 +27,7 @@ class LogSubscriber
     # up the queue, subscriptions and turning colors in logs off.
     #
     # The messages are available in the @logger instance, which is a logger with limited
-    # powers (it actually do not send anything to your output), and you can collect them
+    # powers (it actually does not send anything to your output), and you can collect them
     # doing @logger.logged(level), where level is the level used in logging, like info,
     # debug, warn and so on.
     #