SSL.handshake: Support SSLv2 hello again.

The initialization of the session got lost for SSLv2 hellos
when the storage for several extensions was moved to the session.

Fixes support for *old* ssl clients (like check_http from Nagios).

lib/modules/SSL.pmod/handshake.pike

@@ -1091,6 +1091,7 @@ int(-1..1) handle_handshake(int type, string(0..255) data, string(0..255) raw)
 	  challenge = "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" + challenge;
 	client_random = challenge[sizeof (challenge) - 32..];
 
+	session = context->new_session();
 	{
 	  int(-1..0) err = reply_new_session(cipher_suites,
 					     ({ COMPRESSION_null }) );