fix(dropdown): prevent showing the whole list if showOnFocus is false

When showOnFocus was set to false but the dropdown was opened by clicking on the down arrow icon, then a focus of the input field afterwards was opening the whole menu once, which isn't allowed.

The iconClicked value needs to be reset whenever the dropdown list gets hidden which this PR is
fixing.

Author: lubber-de

src/definitions/modules/dropdown.js

@@ -541,6 +541,7 @@ $.fn.dropdown = function(parameters) {
           } else if( module.can.click() ) {
               module.unbind.intent();
           }
+          iconClicked = false;
         },
 
         hideOthers: function() {