Bug 29056: Remove the demo functionality leftovers

Remove forgotten code of the old legacy demo functionality that was
removed from elsewhere except systempreferences, this code not only
serves no purpose but also is causing some troubles for our customers.

Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>

Signed-off-by: Joonas Kylmälä <joonas.kylmala@iki.fi>

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>

svc/config/systempreferences

@@ -64,10 +64,8 @@ Used to set a single system preference.
 sub set_preference {
     my ( $preference ) = @_;
 
-    unless ( C4::Context->config('demo') ) {
-        my $value = join( ',', $query->param( 'value' ) );
-        C4::Context->set_preference( $preference, $value );
-    }
+    my $value = join( ',', $query->param( 'value' ) );
+    C4::Context->set_preference( $preference, $value );
 
     C4::Service->return_success( $response );
 }
@@ -95,16 +93,14 @@ pref_virtualshelves=0
 =cut
 
 sub set_preferences {
-    unless ( C4::Context->config( 'demo' ) ) {
-        foreach my $param ( $query->param() ) {
-            my ( $pref ) = ( $param =~ /pref_(.*)/ );
+    foreach my $param ( $query->param() ) {
+        my ( $pref ) = ( $param =~ /pref_(.*)/ );
 
-            next if ( !defined( $pref ) );
+        next if ( !defined( $pref ) );
 
-            my $value = join( ',', $query->multi_param( $param ) );
+        my $value = join( ',', $query->multi_param( $param ) );
 
-            C4::Context->set_preference( $pref, $value );
-        }
+        C4::Context->set_preference( $pref, $value );
     }
 
     C4::Service->return_success( $response );