Fix respec warning about duplicate definition

Duplicate definition of 'window dimensioning/positioning'

Author: vkatsikaros

webdriver-spec.html

@@ -1816,7 +1816,7 @@ <h2>Capabilities</h2>
  </tr>
 
  <tr>
-  <td><dfn data-lt="window dimensioning/positioning">Window dimensioning/positioning</dfn>
+  <td><dfn>Window dimensioning/positioning</dfn>
   <td>"<code>setWindowRect</code>"
   <td>boolean
    <td>Indicates whether the remote end supports all of the <a>commands</a> in