Fix IPv6 support (sockaddr size)

Since struct sockaddr is too small to contain an IPv6, we use struct
sockaddr_in6 instead, and we cast it where needed

src/network/socket_handler.cpp

@@ -140,7 +140,7 @@ void SocketHandler::connect(const std::string& address, const std::string& port,
           this->ai_addrlen = rp->ai_addrlen;
           memcpy(&this->ai_addr, rp->ai_addr, this->ai_addrlen);
           memcpy(&this->addrinfo, rp, sizeof(struct addrinfo));
-          this->addrinfo.ai_addr = &this->ai_addr;
+          this->addrinfo.ai_addr = reinterpret_cast<struct sockaddr*>(&this->ai_addr);
           this->addrinfo.ai_next = nullptr;
           // If the connection has not succeeded or failed in 5s, we consider
           // it to have failed

src/network/socket_handler.hpp

@@ -199,7 +199,7 @@ private:
    * again.
    */
   struct addrinfo addrinfo;
-  struct sockaddr ai_addr;
+  struct sockaddr_in6 ai_addr;
   socklen_t ai_addrlen;
 
 protected: