Update bootstrap-switch.less to v1.6

Update bootstrap-switch.less to v1.6

static/less/bootstrap-switch.less

@@ -1,5 +1,5 @@
 /* ============================================================
- * bootstrapSwitch v1.5 by Larentis Mattia @SpiritualGuru
+ * bootstrapSwitch v1.6 by Larentis Mattia @SpiritualGuru
  * http://www.larentis.eu/
  *
  * Enhanced for radiobuttons by Stein, Peter @BdMdesigN