[doc] Update reference to elm-lang.org quote in ux.texi

[Gerald Pfeifer]

Committed.

Gerald

2019-08-17  Gerald Pfeifer  <gerald@pfeifer.com>
 
	* doc/ux.texi (User Experience Guidelines): Update reference.
 
Index: doc/ux.texi
===================================================================
--- doc/ux.texi	(revision 274599)
+++ doc/ux.texi	(working copy)
@@ -9,7 +9,7 @@
 @cindex guidelines, user experience
 
 To borrow a slogan from
- @uref{https://elm-lang.org/blog/compilers-as-assistants, Elm},
+@uref{https://elm-lang.org/news/compilers-as-assistants, Elm},
 
 @quotation
 @strong{Compilers should be assistants, not adversaries.}  A compiler should