fix: typo in error-page template

Author: line-o

src/main/xar-resources/error-page.html

@@ -2,5 +2,5 @@
 <div data-template="templates:surround" data-template-with="templates/page.html" data-template-at="main">
     <h1>An error has occurred</h1>
     <p>An error has been generated by the application.</p>
-    <pre class="error" date-template="templates:error-description"></pre>
+    <pre class="error" data-template="templates:error-description"></pre>
 </div>