lua-factory: Fix setting filesizes
lua-factory: Fix setting filesizes

Filesizes are int64, therefore, don't use grl_data_add_int() for it.

https://bugzilla.gnome.org/show_bug.cgi?id=755556

GNOME/grilo-plugins,GNOME/grilo-plugins,grilofw/grilo-plugins,jasuarez/grilo-plugins,MikePetullo/grilo-plugins,MikePetullo/grilo-plugins,MikePetullo/grilo-plugins,jasuarez/grilo-plugins,grilofw/grilo-plugins