fix another broken href

Author: hjwp

chapter_deploying_validation.asciidoc

@@ -119,12 +119,13 @@ We've done a couple of deploys now, so this is a good time for a little recap:
 * Deploy to live
 * Tag the release 
 
-Deployment procedures evolve and get more complex as projects grow, and it's
-an area that can grow hard to maintain, full of manual checks and procedures,
-if you're not careful to keep things automated.  There's lots more to say about
-this, but it's out of scope for this book.  Do be sure to check out
-<<appendix3>>, and have a read around on the topic of
-"continuous deployment."((("", startref="Dpro17")))
+Deployment procedures evolve and get more complex as projects grow,
+and it's an area that can grow hard to maintain,
+full of manual checks and procedures,
+if you're not careful to keep things automated.
+There's lots more to learn about this, but it's out of scope for this book.
+Look up "continuous delivery" for some background reading.
+((("", startref="Dpro17")))
 
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