[oozie] Add kill widget only when the XML has a kill node

Uncaught ReferenceError: Unable to process binding "template: function (){return { name:'row-template',data:oozieKillRow} }"
Message: Unable to process binding "sortable: function (){return { template:'widget-template',data:widgets,allowDrop:$root.isEditing() && widgets().length < 1,isEnabled:$root.isEditing() && widgets().length < 1,options:{'opacity':0.7,'placeholder':'row-highlight','greedy':true,'stop':function(event,ui){},'helper':function(event){lastWindowScrollPosition = $(window).scrollTop(); var _par = $('<div>');_par.addClass('card card-widget');var _title = $('<h2>');_title.addClass('card-heading simple');_title.text($(event.toElement).text());_title.appendTo(_par);_par.height(80);_par.width(180);return _par;}},dragged:function(widget){widgetDraggedAdditionalHandler(widget)}} }"
Message: widgets is not defined
    at sortable (eval at parseBindingsString (knockout.min.fa8662c7a841.js:68), <anonymous>:3:197)
    at init (knockout-sortable.min.1f7d0fe65aee.js:2)
    at knockout.min.fa8662c7a841.js:72
    at Object.w (knockout.min.fa8662c7a841.js:39)
    at knockout.min.fa8662c7a841.js:71
    at Object.q (knockout.min.fa8662c7a841.js:11)
    at m (knockout.min.fa8662c7a841.js:71)
    at k (knockout.min.fa8662c7a841.js:69)
    at g (knockout.min.fa8662c7a841.js:69)
    at k (knockout.min.fa8662c7a841.js:69)