Use socket opt to prevent a lingering socket after program close

src/server/socket/listeningsocket.cpp

@@ -25,6 +25,12 @@ ListeningSocket::ListeningSocket(int const port)
 		throw std::runtime_error("socket creation error");
 	}
 
+	int enable = 1;
+	if (setsockopt(socketFileDescriptor, SOL_SOCKET, SO_REUSEADDR, &enable, sizeof(int)) < 0)
+	{
+		throw std::runtime_error("setsockopt SO_REUSEADDR failed");
+	}
+
 	socketAddress.sin_family = AF_INET;
 	socketAddress.sin_addr.s_addr = INADDR_ANY;
 	socketAddress.sin_port = htons(port);