SSL: Fix memory leak in d2i_SSL_SESSION

==28360== 98 bytes in 2 blocks are definitely lost in loss record 7 of 7
==28360==    at 0x402AC54: realloc (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so)
==28360==    by 0x40E2D2C: ASN1_STRING_set (asn1_lib.c:393)
==28360==    by 0x40EC22C: asn1_ex_c2i (tasn_dec.c:959)
==28360==    by 0x40EC632: asn1_d2i_ex_primitive (tasn_dec.c:824)
==28360==    by 0x40ED2E6: ASN1_item_ex_d2i (tasn_dec.c:230)
==28360==    by 0x40ED421: ASN1_item_d2i (tasn_dec.c:133)
==28360==    by 0x40F0335: d2i_ASN1_OCTET_STRING (tasn_typ.c:75)
==28360==    by 0x405FD6D: d2i_SSL_SESSION (ssl_asn1.c:367)
==28360==    by 0x405DD6E: ssl3_send_newsession_ticket (s3_srvr.c:2743)
==28360==    by 0x405EA48: ssl3_accept (s3_srvr.c:665)
==28360==    by 0x4067C34: SSL_accept (ssl_lib.c:922)
==28360==    by 0x404E97B: ssl23_get_client_hello (s23_srvr.c:573)

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
s_client: don't call shutdown on non-existing socket descriptor

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>