Update Parser.php

keyname1: value1
    subkeyname1: a value
    subkeyname2:
                                <----Must leave blank here, if previous line-value is empty!!
keyname2: value2




-------------
keyname1: value1
    subkeyname1: a value
    subkeyname2:<EMPTY>
keyname2: value2




<no blank line>catch ParseException "Indentation problem."