Fix graceful shutdown crash.

The cleanup code for optional_api needs to happen after all of the optional
API users and providers have unused/unprovided. Unfortunately, regsitering the
atexit() handler at the beginning of main() isn't soon enough, since module
destructors run after that.
........

Merged revisions 398149 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@398150 65c4cc65-6c06-0410-ace0-fbb531ad65f3

main/asterisk.c

@@ -247,7 +247,6 @@ int daemon(int, int);  /* defined in libresolv of all places */
 #include "asterisk/stasis_endpoints.h"
 #include "asterisk/stasis_system.h"
 #include "asterisk/security_events.h"
-#include "asterisk/optional_api.h"
 
 #include "../defaults.h"
 
@@ -4169,10 +4168,6 @@ int main(int argc, char *argv[])
 			ast_el_read_history(filename);
 	}
 
-#if defined(OPTIONAL_API)
-	ast_register_cleanup(optional_api_cleanup);
-#endif
-
 	ast_json_init();
 	ast_ulaw_init();
 	ast_alaw_init();