fixed typo

Former-commit-id: ab689ef39807a3b584da56799ab2cdf5abf64abe

extension/ui/pages/help.html

@@ -214,7 +214,7 @@
 					</li>
 					<li data-options-label="includeInfobarLabel">Option: include infobar in the saved page
 						<p>Check this option to display the ℹ button at the top right of the page when viewing a saved
-							page in a browser where SingleFileZ is not installed.</p>
+							page in a browser where SingleFile is not installed.</p>
 					</li>
 				</ul>
 				<p>Stylesheets</p>