stroke: Add missing include for UINT16_MAX

Fixes the build on FreeBSD.

Fixes #988.

src/starter/starterstroke.c

@@ -16,6 +16,7 @@
 
 #include <unistd.h>
 #include <stdlib.h>
+#include <stdint.h>
 #include <string.h>
 
 #include <credentials/auth_cfg.h>

src/stroke/stroke.c

@@ -17,6 +17,7 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <stdio.h>
+#include <stdint.h>
 #include <string.h>
 #include <getopt.h>