Grammar tweak.

Doc/lib/emailparser.tex

@@ -22,7 +22,7 @@ Note that the parser can be extended in limited ways, and of course
 you can implement your own parser completely from scratch.  There is
 no magical connection between the \module{email} package's bundled
 parser and the \class{Message} class, so your custom parser can create
-message object trees in any way it find necessary.
+message object trees any way it finds necessary.
 
 The primary parser class is \class{Parser} which parses both the
 headers and the payload of the message.  In the case of