Fix for Bug 7085 - Problems with searching for orders in acquisitions

Fix for Bug 7085 - Problems with searching for orders in acquisitions

Changing "if ( defined $input )" to "if ( $input )" in the section
of the script which builds the order search query seems to give
successful searches where they didn't exist before. Searches from
the advanced order search screen work with title, author, vendor,
basket number, date, etc.

Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Searches for date ranges, title and author keywords give
me the correct results now.