Bug 24016: manager_id in Koha::Patron::Message->store should not depend on userenv alone

Koha::Patron::Message->store has this

    my $userenv = C4::Context->userenv;
    $self->manager_id( $userenv ? $userenv->{number} : undef);

This breaks in REST API when userenv is not set.

Let API user pass manager_id without relying on C4::Context->userenv.

To test:
1. prove t/db_dependent/Koha/Patron/Messages.t
2. Observe success

Sponsored-by: Koha-Suomi Oy
Signed-off-by: Maryse Simard <maryse.simard@inlibro.com>
Signed-off-by: Joonas Kylmälä <joonas.kylmala@helsinki.fi>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>

Koha/Patron/Message.pm

@@ -49,8 +49,10 @@ sub store {
               and $self->message_type
               and $self->branchcode;
 
-    my $userenv = C4::Context->userenv;
-    $self->manager_id( $userenv ? $userenv->{number} : undef);
+    unless (defined $self->manager_id) {
+        my $userenv = C4::Context->userenv;
+        $self->manager_id( $userenv ? $userenv->{number} : undef);
+    }
 
     C4::Log::logaction( "MEMBERS", "ADDCIRCMESSAGE", $self->borrowernumber, $self->message )
         if C4::Context->preference("BorrowersLog");