fix link rot on web servers page

mattmakai · mattmakai · commit 7478a5a0a5c9 · 2017-01-03T09:29:13.000-08:00
diff --git a/all.html b/all.html
@@ -6033,9 +6033,6 @@ <h2>Web server resources</h2>
 is provided by W3C.</p>
 </li>
 <li>
-<p><a href="http://ibuildings.nl/blog/2013/03/4-http-security-headers-you-should-always-be-using">4 HTTP Security Headers You Should Always Be Using</a></p>
-</li>
-<li>
 <p>If you're looking to learn about web servers by building one, here's
   <a href="http://ruslanspivak.com/lsbaws-part1/">part one</a>,
   <a href="http://ruslanspivak.com/lsbaws-part2/">part two</a> and <a href="http://ruslanspivak.com/lsbaws-part3/">part three</a> 
diff --git a/source/content/pages/08-web-app-deployment/16-web-servers.markdown b/source/content/pages/08-web-app-deployment/16-web-servers.markdown
@@ -94,8 +94,6 @@ possible.
 [HTTP status codes](http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html)
 is provided by W3C.
 
-* [4 HTTP Security Headers You Should Always Be Using](http://ibuildings.nl/blog/2013/03/4-http-security-headers-you-should-always-be-using)
-
 * If you're looking to learn about web servers by building one, here's
   [part one](http://ruslanspivak.com/lsbaws-part1/),
   [part two](http://ruslanspivak.com/lsbaws-part2/) and [part three](http://ruslanspivak.com/lsbaws-part3/) 
diff --git a/web-servers.html b/web-servers.html
@@ -118,9 +118,6 @@ <h2>Web server resources</h2>
 is provided by W3C.</p>
 </li>
 <li>
-<p><a href="http://ibuildings.nl/blog/2013/03/4-http-security-headers-you-should-always-be-using">4 HTTP Security Headers You Should Always Be Using</a></p>
-</li>
-<li>
 <p>If you're looking to learn about web servers by building one, here's
   <a href="http://ruslanspivak.com/lsbaws-part1/">part one</a>,
   <a href="http://ruslanspivak.com/lsbaws-part2/">part two</a> and <a href="http://ruslanspivak.com/lsbaws-part3/">part three</a> 
