[SSE] Set empty range for function arguments

apps/spreadsheeteditor/main/app/view/CellRangeDialog.js

@@ -81,7 +81,7 @@ define([
                 el          : $('#id-dlg-cell-range'),
                 name        : 'range',
                 style       : 'width: 100%;',
-                allowBlank  : false,
+                allowBlank  : this.options.allowBlank || false,
                 blankError  : this.txtEmpty,
                 validateOnChange: true
             });

apps/spreadsheeteditor/main/app/view/FormulaWizard.js

@@ -356,6 +356,7 @@ define([
                 };
 
                 var win = new SSE.Views.CellRangeDialog({
+                    allowBlank: true,
                     handler: handlerDlg
                 }).on('close', function() {
                     input.setValue(changedValue);