modification.php > fix new lines for replace value

To avoid new lines - which could break the code - I propose to trim the $replace value.
If inside the ocmod this is written:
``<add position="replace">
				<![CDATA[
					replace_value
				]]>
			</add>``
otherwise the ocmod has always to be this way:
``<add position="replace">
				<![CDATA[replace_value]]>
			</add>``