Astobj2: Fix initialization order of refdebug and AO2_DEBUG.

This ensures that refdebug is initialized before AO2_DEBUG if
both are enabled, since AO2_DEBUG allocates a container.

This change also makes AO2_DEBUG initialization critical, a
failure will abort Asterisk startup.  This is needed since
the failure would be caused by reg_containers allocation
failure, and that would result in a segmentation fault by
ao2_container_register later in startup.

ASTERISK-25048 #close
Reported by: Corey Farrell

Change-Id: I9a243ea3fc5653b48b931ba6d61971cb2e530244