Fix FastAGI to not wait for the non-existant pid

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@46141 65c4cc65-6c06-0410-ace0-fbb531ad65f3

res/res_agi.c

@@ -1869,6 +1869,7 @@ static enum agi_result run_agi(struct ast_channel *chan, char *request, AGI *agi
 					returnstatus = -1;
 				if (option_verbose > 2) 
 					ast_verbose(VERBOSE_PREFIX_3 "AGI Script %s completed, returning %d\n", request, returnstatus);
+				if (pid > 0)
 					waitpid(pid, status, 0);
 				/* No need to kill the pid anymore, since they closed us */
 				pid = -1;