#915: Fix file descriptor leak in og_socket_server_init() from exit path

Call close() to release the socket in the event of an error.

infer says:

sources/ogAdmServer.cpp:1244: error: RESOURCE_LEAK
  resource acquired by call to `socket()` at line 1236, column 6 is not released after line 1244, column 3.
  1242.   			 sizeof(on));
  1243.   	if (res < 0) {
  1244. > 		syslog(LOG_ERR, "cannot set broadcast socket\n");
  1245.   		return false;
  1246.   	}

Not a real problem since OS releases process resources if the server
cannot bind to the port, but just to be correct here.

sources/ogAdmServer.cpp

@@ -4356,6 +4356,7 @@ static int og_socket_server_init(const char *port)
 	local.sin_port = htons(atoi(port));
 
 	if (bind(sd, (struct sockaddr *) &local, sizeof(local)) < 0) {
+		close(sd);
 		syslog(LOG_ERR, "cannot bind socket\n");
 		return -1;
 	}