expose glance_port,protocol as glance.port,protocol

These values are available in metadata with underscores but
they are accessed by nova with dots.
Make them available with dots.

Required by: Idccc0d60c9f6b17a853c6de1bbea64bfc7e028b2
Change-Id: I5fe952f850339465de128e56e45c9bbda011ce7f
Merge "expose glance_port,protocol as glance.port,protocol"