[GPEEngine] Do not free the list in set_active_plugin_list()
[GPEEngine] Do not free the list in set_active_plugin_list()

As the list is passed as an argument to set_active_plugin_list(), there
is no reason to free it, as we can't even know it is free-able.

GNOME/libpeas,gregier/libpeas,chergert/libpeas,Distrotech/libpeas,gregier/libpeas,GNOME/libpeas,chergert/libpeas,gregier/libpeas,Distrotech/libpeas,gregier/libpeas,chergert/libpeas,Distrotech/libpeas