Bug 28569: In opac-suggestions.pl preselect user library

Bug 28569: In opac-suggestions.pl preselect user library

In OPAC new purchase suggestion opac-suggestions.pl for library combobox :
actually first value is selected, user library should be selected.

Test plan :
1) Create a new library named 'ZZZ top'
2) Set this library on a user U1
2) Loggin at OPAC with user U1
3) Create a new suggestion
=> Check library 'ZZZ top' is preselected

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>