Fix SF #1442937, Bad Coroutine link

Doc/whatsnew/whatsnew25.tex

@@ -246,7 +246,7 @@ some fancier uses of generators as coroutines.}
 \seeurl{http://en.wikipedia.org/wiki/Coroutine}{The Wikipedia entry for 
 coroutines.}
 
-\seeurl{http://www.sidhe.org/~dan/blog/archives/000178.html}{An
+\seeurl{http://www.sidhe.org/\~{}dan/blog/archives/000178.html}{An
 explanation of coroutines from a Perl point of view, written by Dan
 Sugalski.}