Follow Apple's lead and do not fail krb5_set_config_files() simply
because one of the files in the profile list fails to parse correctly.
Doing so can lead to hard to find failures and could lead to an end
user shooting themselves in the foot and no longer be able to login
to their system to fix it.
Parse as many of the files as we can. Only fail krb5_set_config_files()
if init_context_from_config_file() fails.
Change-Id: I122664c6d707a5f926643808ba414bf4f681f8b8