Explicitly initialize struct tm with zeroes

This is recommended by the manual as strptime(), in principle,
might only touch the fields it parses from the string. Given
the struct tm implementations differ from operating system to
operating system, we make sure and set everything to zero
before passing it to strptime().

Signed-off-by: Laslo Hunhold <dev@frign.de>

http.c

@@ -350,7 +350,7 @@ http_send_response(int fd, struct request *r)
 {
 	struct in6_addr res;
 	struct stat st;
-	struct tm tm;
+	struct tm tm = { 0 };
 	size_t len, i;
 	off_t lower, upper;
 	int hasport, ipv6host;