Remove default email value from Prebid sample site to prevent opted-out email confusion

Author: eiman-eltigani-ttd

static/examples/cstg-prebid-example/index.html

@@ -133,7 +133,6 @@ <h1>UID2 Prebid.js Client-Side Integration Example</h1>
           name="email"
           placeholder="Enter an email address"
           style="border-style: none"
-          value="test@example.com"
         />
       </div>
       <div><button type="button" class="button" id="login">Generate UID2</button></div>