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/cli.c b/src/cli.c
index 687796f..d1d1e96 100644
--- a/src/cli.c
+++ b/src/cli.c
@@ -359,7 +359,7 @@
 				set = 0;
 				break;
 			}
-			if (parse_process_number(args[cur_arg], &set, NULL, err)) {
+			if (parse_process_number(args[cur_arg], &set, LONGBITS, NULL, err)) {
 				memprintf(err, "'%s %s' : %s", args[0], args[1], *err);
 				return -1;
 			}