Fix polarssl segfault

[StefanNyman]

https://polarssl.org/tech-updates/security-advisories/polarssl-security-advisory-2014-02
#0: 0x549643 gcm_auth_decrypt in gcm.c:317
#1: 0x4ceeff ? in stack.s:85
#2: 0x53f5e0 ssl_decrypt_buf in ssl_tls.c:1275
#3: 0x4ceeff ? in stack.s:85
#4: 0x53f09f ssl_read_record in ssl_tls.c:2006
#5: 0x4ceeff ? in stack.s:85
#6: 0x5425c7 ssl_read in ssl_tls.c:3703
#7: 0x52dcc2 __librcd_ifc_join__tls_read in polar.c:118
#8: 0x4ceeff ? in stack.s:85
#9: 0x52dc32 tls_read in polar.c:112
#10: 0x52f45a tls_rio_read in polar.c:323
#11: 0x4ceeff ? in stack.s:85
#12: 0x4d8f15 rio_read_direct in ?:?
#13: 0x4d9753 rio_peek in rio.c:1403
#14: 0x490b7c http_session in wsr.c:360
#15: 0x4ceeff ? in stack.s:85
#16: 0x48ef22 _http_connection_fiber in wsr.c:821
#17: 0x4ceeff ? in stack.s:85

[simonlindholm]

Hah, looks like all of issues 1-17 now say that they are referenced by this issue. @hannes-landeholm, how about changing the stack dump format to avoid making accidental issue references?

[hnsl]

Ugh...

[hnsl]

This should have been fixed in the polar-ssl generator update. We might want to make a new issue for @simonlindholm comment above.

[simonlindholm]

Done, because why not (#22).