Update demo-event-on-select.html

Change to use the new, clearly labelled function.

Author: flouc001

examples/demo-event-on-select.html

@@ -64,7 +64,7 @@
 
   <h3>Select2 theme</h3>
   <p>Selected: {{person.selected}}</p>
-  <ui-select ng-model="person.selected" theme="select2" on-select="someFunction($item, $model)" ng-disabled="disabled" style="min-width: 300px;" title="Choose a person">
+  <ui-select ng-model="person.selected" theme="select2" on-select="onSelectCallback($item, $model)" ng-disabled="disabled" style="min-width: 300px;" title="Choose a person">
     <ui-select-match placeholder="Select a person in the list or search his name/age...">{{$select.selected.name}}</ui-select-match>
     <ui-select-choices repeat="person.email as person in people | propsFilter: {name: $select.search, age: $select.search}">
       <div ng-bind-html="person.name | highlight: $select.search"></div>