MDL-27654 Insert a space into the somefieldrequired string

lang/en/form.php

@@ -55,7 +55,7 @@
 $string['selectallornone'] = 'Select all/none';
 $string['selected'] = 'Selected';
 $string['showadvanced'] = 'Show advanced';
-$string['somefieldsrequired'] = 'There are required fields in this form marked{$a}.';
+$string['somefieldsrequired'] = 'There are required fields in this form marked {$a}.';
 $string['time'] = 'Time';
 $string['timeunit'] = 'Time unit';
 $string['timing'] = 'Timing';