Update guestbook link image in index.html for improved visuals

Author: ZaneThePython

buttons/gb.gif

@@ -20,7 +20,7 @@ <h4 class="nav-item">Navigator Ultimate <p class="mini-text">Trial Version</p></
             <br><br>
             <a href="https://zane.org/links.html"><img class="nav-item" src="https://anlucas.neocities.org/globe05.gif"><br>Links</a>
             <br><br>
-            <a href="https://zaney.atabook.org/"><img class="nav-item" src="https://anlucas.neocities.org/Simple_book.gif"><br>Guestbook</a>
+            <a href="https://zaney.atabook.org/"><img class="nav-item" src="https://zane.org/buttons/gb.gif"><br>Guestbook</a>
         </div>
     </header>
     <div class="content">