Fix typo in 'How to Configure Monolog to Email Errors'

Author: jeroennoten

logging/monolog_email.rst

@@ -141,7 +141,7 @@ is then passed onto the ``deduplicated`` handler.
 The ``deduplicated`` handler keeps all the messages for a request and then
 passes them onto the nested handler in one go, but only if the records are
 unique over a given period of time (60 seconds by default). If the records are
-duplicates they are discarded. Adding this handler reduces the amount of
+duplicated they are discarded. Adding this handler reduces the amount of
 notifications to a manageable level, specially in critical failure scenarios.
 You can adjust the time period using the ``time`` option: