Markup fix

Doc/whatsnew/whatsnew25.tex

@@ -75,7 +75,7 @@ contents = ((doc + '\n') if doc else '')
 \end{verbatim}
 
 I read the above statement as meaning ``here \var{contents} is 
-usually assigned a value of \code{doc+'\n'}; sometimes 
+usually assigned a value of \code{doc+'\e n'}; sometimes 
 \var{doc} is empty, in which special case an empty string is returned.''  
 I doubt I will use conditional expressions very often where there 
 isn't a clear common and uncommon case.