This patch is necessary because lwip always returns EALREADY if the
connection is established but never EISCONN. So most programs will
fail to connect because they at one point while connecting expect to
get EISCONN.

--- a/src/api/sockets.c
+++ b/src/api/sockets.c
@@ -214,7 +214,7 @@ static const int err_to_errno_table[] = {
   EINVAL,        /* ERR_VAL        -6      Illegal value.           */
   EWOULDBLOCK,   /* ERR_WOULDBLOCK -7      Operation would block.   */
   EADDRINUSE,    /* ERR_USE        -8      Address in use.          */
-  EALREADY,      /* ERR_ISCONN     -9      Already connected.       */
+  EISCONN,       /* ERR_ISCONN     -9      Already connected.       */
   ECONNABORTED,  /* ERR_ABRT       -10     Connection aborted.      */
   ECONNRESET,    /* ERR_RST        -11     Connection reset.        */
   ENOTCONN,      /* ERR_CLSD       -12     Connection closed.       */
