Fix drawing in Figure 1

From Steve Fenter
                                  ********************************
                                 *                                *
                                *            +--------+            *
                               *   TLS       |  Web   |             *
                              * Termination  + Server +              *
                             *      |       /|        |\              *
   +---------+  +----------+ * +----|-----+/ +--------+ \+----------+ *
   |         |  |          | * |   Load   +              + Back-end | *
   | Browser +--+ Internet |-*-+ Balancer |              |  Server  | *
   |         |  |          | * |    |     +              +          | *
   +---------+  +----------+ * +----------+\ +--------+ /+----------+ *
                             *      |      .\|  Web   |/.             *
                             *            .  + Server +  .            *
                             *            .  |        |  .            *
                             *            .  +--------+  .            *
                             *            .              .            *
                             *            .   --------   .            *
                             *             . /  TLS   \ .             *
                             *              | Decrypter|              *
                              *              \        /              *
                               *              --------              *
                                *                                  *
                                 *** Enterprise Network Boundary **

                                    |
   <-----Ephemeral Key (EC)DHE----->|<--------Static Key ECDHE-------->
                                    |

             Figure 1: Enterprise TLS Decryption Architecture
rdroms / draft-green-tls-static-dh-in-tls13

Fix drawing in Figure 1 #29
