cmake: uselib: do not support optional (use find_package for that).
cmake: uselib: do not support optional (use find_package for that).

aldebaran/qibuild,aldebaran/qibuild,dmerejkowsky/qibuild,aldebaran/qibuild,dmerejkowsky/qibuild,dmerejkowsky/qibuild,aldebaran/qibuild,dmerejkowsky/qibuild,dmerejkowsky/qibuild