config: BUG: Restore ability for non-templ to be used as base objs in config.

My recent refactor of config.c accidentally removed the capability for an
object to inherit from a non-template object.

This patch restores the capability to inherit from both template and
non-template objects.

Tested-by: George Joseph
Reported-by: Scott Griepentrog
ASTERISK-24487 #close

Review: https://reviewboard.asterisk.org/r/4147/
........

Merged revisions 427227 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: http://svn.asterisk.org/svn/asterisk/branches/13@427228 f38db490-d61c-443f-a65b-d21fe96a405b