Bug 6017 : MT3157 : editing an attribute lead to Error500

Bug 6017 : MT3157 : editing an attribute lead to Error500

Editing an extended attribute in the extended attribute tab would lead to an Error500
This patch adds some checks for values before UPDATE in SQLHelper.pm
And Adds some checks also befaore calling ModMember in members/memberentry

Signed-off-by: Stéphane Delaune <stephane.delaune@biblibre.com>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>
(cherry picked from commit e2fd348f7f53d4a9a69bc26062c466aa6b79c370)

Signed-off-by: Chris Nighswonger <chris.nighswonger@gmail.com>