Bug 15479 Make ILS cardnumber comparison case insensitive

Bug 15479 Make ILS cardnumber comparison case insensitive

The borrowers table is defined COLLATE=utf8_unicode_ci which means
that cardnumbers may be saved in either lowercase or uppercase and
these are considered equivalent.
The server was performing a case sensitive comparison between
the incoming patron identifier and that retrieved from the db
As a result some renewals were rejected as being on loan to
another borrower if the stored cardnumber differed in case.

Make code comparison comply with db.

Signed-off-by: Mark Tompsett <mtompset@hotmail.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Brendan Gallagher brendan@bywatersolutions.com
(cherry picked from commit 203659ee60b25614eecd01f69e23e3be57952707)
Signed-off-by: Julian Maurice <julian.maurice@biblibre.com>