Bug 267211: fix 'clipboard' misspelling.

browser/components/help/locale/en-US/forieusers.xhtml

@@ -66,7 +66,7 @@
     <td>Bookmarks Toolbar</td>
   </tr>
   <tr>
-    <td><span class="noMac">Copy Shortcut</span><span class="mac">Copy Link to Clipbord</span></td>
+    <td><span class="noMac">Copy Shortcut</span><span class="mac">Copy Link to Clipboard</span></td>
     <td>Copy Link Location</td>
   </tr>
   <tr>