Tiny typo

Added an "s"!

Author: greiginsydney

skype/skype-ps/skype/Set-CsImConfiguration.md

@@ -55,7 +55,7 @@ Accept wildcard characters: False
 ```
 
 ### -EnableOfflineIm
-Enables or disable Offline Instant Messaging.
+Enables or disables Offline Instant Messaging.
 
 ```yaml
 Type: Boolean