Change type of keyboardinput to password to make sure that you can write parenthesis on iOS devices.

vnc.html

@@ -64,7 +64,7 @@
                 <input type="image" alt="Keyboard" src="images/keyboard.png"
                     id="showKeyboard" class="noVNC_status_button"
                     value="Keyboard" title="Show Keyboard"/>
-                <input type="email" id="keyboardinput" autocapitalize="off"
+                <input type="password" id="keyboardinput" autocapitalize="off"
                     autocorrect="off" autocomplete="off" spellcheck="false">
                 <div id="noVNC_extra_keys">
                     <input type="image" alt="Extra keys" src="images/showextrakeys.png"