MINOR: cfgparse: make the process/thread parser support a maximum value

It was hard-wired to LONGBITS, let's make it configurable depending on the
context (threads, processes).
diff --git a/src/cfgparse-global.c b/src/cfgparse-global.c
index 5a92d9b..2cdcf76 100644
--- a/src/cfgparse-global.c
+++ b/src/cfgparse-global.c
@@ -949,14 +949,14 @@
 		if ((slash = strchr(args[1], '/')) != NULL)
 			*slash = 0;
 
-		if (parse_process_number(args[1], &proc, &autoinc, &errmsg)) {
+		if (parse_process_number(args[1], &proc, LONGBITS, &autoinc, &errmsg)) {
 			ha_alert("parsing [%s:%d] : %s : %s\n", file, linenum, args[0], errmsg);
 			err_code |= ERR_ALERT | ERR_FATAL;
 			goto out;
 		}
 
 		if (slash) {
-			if (parse_process_number(slash+1, &thread, NULL, &errmsg)) {
+			if (parse_process_number(slash+1, &thread, MAX_THREADS, NULL, &errmsg)) {
 				ha_alert("parsing [%s:%d] : %s : %s\n", file, linenum, args[0], errmsg);
 				err_code |= ERR_ALERT | ERR_FATAL;
 				goto out;