res_pjsip: Fix leak of fake_auth references.

pjsip_distributor leaks references to fake_auth when the default realm
has not changed.

ASTERISK-27306

Change-Id: I3fcf103b3680ad2d1d4610dcd6738eeaebf4d202

res/res_pjsip/pjsip_distributor.c

@@ -1142,9 +1142,9 @@ static void global_loaded(const char *object_type)
 		fake_auth = alloc_artificial_auth(default_realm);
 		if (fake_auth) {
 			ao2_global_obj_replace_unref(artificial_auth, fake_auth);
-			ao2_ref(fake_auth, -1);
 		}
 	}
+	ao2_cleanup(fake_auth);
 
 	ast_sip_get_unidentified_request_thresholds(&unidentified_count, &unidentified_period, &unidentified_prune_interval);