Mark errata fixed in the 5th print

Author: marijnh

html/errata.html

@@ -67,7 +67,7 @@ <h2>Chapter 11</h2>
 
 <h2>Chapter 14</h2>
 
-<p><strong>Page 231</strong> <em>Moving Through the Tree</em>: Below
+<p><strong>Page 231</strong> (5th) <em>Moving Through the Tree</em>: Below
 the code example, the text claims
 that <code>for</code>/<code>of</code> loops don't work on DOM child
 lists. But in current (even as of the book's release) browsers they
@@ -93,7 +93,7 @@ <h2>Chapter 16</h2>
 
 <h2>Chapter 19</h2>
 
-<p><strong>Page 336</strong> <em>The State</em>: The text mentions the
+<p><strong>Page 336</strong> (5th) <em>The State</em>: The text mentions the
 property <code>fillColor</code> where it should
 say <code>fillStyle</code> instead.