Fixed the issue with validating the form on Cancel button.

(Redmine issue: #7519)

lib/hawat/static/js/hawat-jquery.js

@@ -80,6 +80,11 @@ $(function() {
         $('#datetimepicker-from-2').data("DateTimePicker").maxDate(e.date);
     });
 
+    // Disable built-in JS form validation in case the form`s cancel button is clicked.`
+    $('input[type="submit"][value="Cancel"]').click(function(){
+        $(this).parents('form:first').attr('novalidate', 'novalidate');
+    });
+
     // Initialize linked date and datetime picker components.
     $('#datetimepicker-hm-from').datetimepicker({
         locale: GLOBAL_LOCALE,