glib: add missing lock statements for Objects collection
glib: add missing lock statements for Objects collection

When accessing the static Objects collection in GLib.Object
class, a lock was held in some places but not all of them.
Brought up by Alan McGovern.

Signed-off-by: Bertrand Lorentz <eb7ac131ef7bff6d2ebccd6e5bf9a7cb6485cf2c@gmail.com>

antoniusriha/gtk-sharp,openmedicus/gtk-sharp,akrisiun/gtk-sharp,openmedicus/gtk-sharp,antoniusriha/gtk-sharp,orion75/gtk-sharp,openmedicus/gtk-sharp,Gankov/gtk-sharp,akrisiun/gtk-sharp,sillsdev/gtk-sharp,openmedicus/gtk-sharp,openmedicus/gtk-sharp,openmedicus/gtk-sharp,akrisiun/gtk-sharp,sillsdev/gtk-sharp,akrisiun/gtk-sharp,openmedicus/gtk-sharp,Gankov/gtk-sharp,akrisiun/gtk-sharp,Gankov/gtk-sharp,orion75/gtk-sharp,orion75/gtk-sharp,sillsdev/gtk-sharp,antoniusriha/gtk-sharp,Gankov/gtk-sharp,antoniusriha/gtk-sharp,antoniusriha/gtk-sharp,orion75/gtk-sharp,Gankov/gtk-sharp,Gankov/gtk-sharp,sillsdev/gtk-sharp,sillsdev/gtk-sharp,orion75/gtk-sharp