ignore SIGPIPE

bad clients can shutdown the socket and we will exit due to a SIGPIPE.
it ain’t fun.

gmid.c

@@ -25,6 +25,7 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <poll.h>
+#include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -668,6 +669,8 @@ main(int argc, char **argv)
 	struct tls_config *conf;
 	int sock, ch;
 
+	signal(SIGPIPE, SIG_IGN);
+
 	while ((ch = getopt(argc, argv, "c:d:hk:")) != -1) {
 		switch (ch) {
 		case 'c':