www/abcbus.html: new MAX80 protocol -> new abc80sim version needed

Update the documentation to indicate new version needed for abc80sim.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

esp32/www/abcbus.html

@@ -43,7 +43,7 @@
 	</label>
 	<p class="help">The network server software is integrated
 	  with <a href="https://www.abc80.org/pub/abc80sim/">abc80sim</a>
-	  version 3.7.0 or later.</p>
+	  version 3.7.5 or later.</p>
       </fieldset>
       <button class="submit" type="submit" disabled>Update configuration</button>
     </form>