deselectAll should do so in singleselect as well

Changing the value of a single select dropdown using 'select' method does not clear the previous values because, deselectAll method won't deselect radio button's selections. It handled only checkboxes. So removed the checkbox specific filter in jquery selector.

dist/js/bootstrap-multiselect.js

@@ -1131,7 +1131,7 @@
             var justVisible = typeof justVisible === 'undefined' ? true : justVisible;
             
             if(justVisible) {              
-                var visibleCheckboxes = $("li input[type='checkbox']:not(:disabled)", this.$ul).filter(":visible");
+                var visibleCheckboxes = $("li input:not(:disabled)", this.$ul).filter(":visible");
                 visibleCheckboxes.prop('checked', false);
                 
                 var values = visibleCheckboxes.map(function() {
@@ -1147,7 +1147,7 @@
                 }
             }
             else {
-                $("li input[type='checkbox']:enabled", this.$ul).prop('checked', false);
+                $("li input:enabled", this.$ul).prop('checked', false);
                 $("option:enabled", this.$select).prop('selected', false);
                 
                 if (this.options.selectedClass) {