client: Add missing include for FreeBSD

Author: nikias

src/client.c

@@ -31,6 +31,7 @@
 #include <unistd.h>
 #include <sys/types.h>
 #include <sys/socket.h>
+#include <netinet/in.h>
 #include <netinet/tcp.h>
 #include <sys/un.h>
 #include <arpa/inet.h>