Modified mongotop.txt file as there was type with the word 'ruining'

Author: Mark Hillick

source/reference/mongotop.txt

@@ -57,7 +57,7 @@ Options
 
    Specifies a resolvable hostname for the ``mongod`` from which you
    want to export data. By default :program:`mongotop` attempts to
-   connect to a MongoDB process ruining on the localhost port number
+   connect to a MongoDB process running on the localhost port number
    ``27017``.
 
    Optionally, specify a port number to connect a MongboDB instance