Bug 1588412 - (part 1) Fix grammer in comment r=mayhemer

Differential Revision: https://phabricator.services.mozilla.com/D49100

--HG--
extra : moz-landing-system : lando

netwerk/protocol/http/nsIHttpProtocolHandler.idl

@@ -174,7 +174,7 @@ interface nsIHttpProtocolHandler : nsIProxiedProtocolHandler
 #define NS_HTTP_ON_EXAMINE_CACHED_RESPONSE_TOPIC "http-on-examine-cached-response"
 
 /**
- * The observer of this topic is notified before before the response for a HTTP
+ * The observer of this topic is notified before the response for a HTTP
  * load is available. The "subject" of the notification is the
  * nsIProcessSwitchRequestor instance. Observers may call "switchProcessTo" to
  * perform a process switch while this is being run.