0039658: The Web POS is blocked when it throws an exception in the balance.

diff --git a/web/org.openbravo.retail.posterminal/js/model/order.js b/web/org.openbravo.retail.posterminal/js/model/order.js
--- a/web/org.openbravo.retail.posterminal/js/model/order.js
+++ b/web/org.openbravo.retail.posterminal/js/model/order.js
@@ -1531,8 +1531,14 @@
           OB.POS.hwserver.getWeight(function (data) {
             if (data.exception) {
               OB.UTIL.showConfirmation.display('', data.exception.message);
+	      if (callback) {
+                callback(false, null);
+              }
             } else if (data.result === 0) {
               OB.UTIL.showConfirmation.display('', OB.I18N.getLabel('OBPOS_WeightZero'));
+              if (callback) {
+                callback(false, null);
+              }
             } else {
               line = me.createLine(p, data.result, options, attrs);
             }