[selectors-4] Fix typo https://lists.w3.org/Archives/Public/www-style/2018Feb/0002.html

Author: fantasai

selectors-4/Overview.bs

@@ -3825,7 +3825,7 @@ Changes</h2>
 			see <a href="https://lists.w3.org/Archives/Public/www-style/2014Jan/0607.html">discussion</a>.
 		<li>Defined <a>specificity</a> of a <a>selector list</a>. (Why?)
 		<li>Required quotes around '':lang()'' values involving an asterisk;
-			only language codes which happen to bhe CSS identifiers can be used unquoted.
+			only language codes which happen to be CSS identifiers can be used unquoted.
 	</ul>
 
 	Note: The 1 February 2018 draft included an inadvertent commit of unfinished work;