Build Error

- Missing include.

src/TLSClient.cpp

@@ -32,6 +32,7 @@
 #include <iostream>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <TLSClient.h>
 #include <sys/socket.h>
 #include <arpa/inet.h>