[hackers] [sic] fix include: include sys/select.h for select(2) and FD_(ZERO|SET) || Hiltjo Posthuma

[git]

commit ec293427a0cc2ef7f561a60347ce940d567efb72
Author:     Hiltjo Posthuma <hil...@codemadness.org>
AuthorDate: Sun Oct 11 14:51:35 2020 +0200
Commit:     Hiltjo Posthuma <hil...@codemadness.org>
CommitDate: Sun Oct 11 14:51:35 2020 +0200

    fix include: include sys/select.h for select(2) and FD_(ZERO|SET)
    
    Reported by nonterminal on IRC, thanks!

diff --git a/sic.c b/sic.c
index ecefaf2..774f357 100644
--- a/sic.c
+++ b/sic.c
@@ -1,4 +1,6 @@
  /* See LICENSE file for license details. */
+#include <sys/select.h>
+
 #include <ctype.h>
 #include <errno.h>
 #include <stdarg.h>