Update sign-up.jsp

Patch for solve problem with recaptcha over https
NewReCaptcha method in sing-up.jsp changed to newSecureReCaptcha - whatever you use, 9090 or 9091 - captcha always will comes via HTTPS
(http://community.igniterealtime.org/message/238655)

src/plugins/registration/src/web/sign-up.jsp

@@ -57,7 +57,7 @@
     RegistrationPlugin plugin = (RegistrationPlugin) webManager.getXMPPServer().getPluginManager().getPlugin("registration");
     ReCaptcha reCaptcha = null;
     if (plugin.reCaptchaEnabled()) {
-        reCaptcha = ReCaptchaFactory.newReCaptcha(
+        reCaptcha = ReCaptchaFactory.newSecureReCaptcha(
                 plugin.getReCaptchaPublicKey(),
                 plugin.getReCaptchaPrivateKey(),
                 plugin.reCaptchaNoScript());
@@ -267,4 +267,4 @@ document.f.username.focus();
 <% } %>
 
 </body>
-</html>
\ No newline at end of file
+</html>