[Koha] error from C4::Context

[tommaso spazzali]

Hello everybody,

I noticed that saving MARC subfield structure for any tag raise an error
in the /var/log/koha/library/intranet-error.log

the error is:

in Koha 3.22
 Use of uninitialized value in string eq at
/usr/share/koha/intranet/cgi-bin/admin/marc_subfields_structure.pl line 292


in Koha 16.05.3
 Use of uninitialized value in string eq at
/usr/share/koha/intranet/cgi-bin/admin/marc_subfields_structure.pl line 288

and the line contains:

unless ( C4::Context->config('demo') or C4::Context->config('demo') eq 1 ) {


hope this is not a problem

ciao
tommaso