[css-cascade] Revert earlier change that was commited by mistake.

Author: SimonSapin

css-cascade/Overview.src.html

@@ -118,9 +118,6 @@ <h2 id="at-import">
 	<p>
 		The <i>origin</i> of an imported style sheet is the same as the <i>origin</i> of the style sheet that imported it.
 
-	<p>
-		The <i>environment encoding</i> of an imported style sheet is the encoding of the style sheet that imported it. [[CSS3SYN]]
-
 <h3 id='content-type'>
 Content-Type of CSS Style Sheets</h3>