www: remove meaningless host type abc80/4680

Cards cannot be made fully functional in an expansion box without
rejumpering the box.

esp32/www/abcbus.html

@@ -23,10 +23,6 @@
 	      <input type="radio" name="abc.hosttype" value="1" />
 	      <span>ABC80</span>
 	    </label>
-	    <label class="abc80-4680">
-	      <input type="radio" name="abc.hosttype" value="2" />
-	      <span>ABC80/4680 (expansion box)</span>
-	    </label>
 	    <label class="abc800">
 	      <input type="radio" name="abc.hosttype" value="3" />
 	      <span>ABC800C/M</span>