I solved the problem, by using Remove transform, as shown below
<configuration xmlns:xdt="http://schemas.microsoft.com/XML-Document-Transform">
....
<system.webServer>
<rewrite>
<rules>
<rule name="RulaNameToRemove"
xdt:Transform="Remove"
xdt:Locator="Match(name)" >
</rule>
</rules>
</rewrite>
</system.webServer>
</configuration>