configure: detect latest boringssl

Since boringssl brought back DES_set_odd_parity again, it cannot be used
to differentiate from boringssl. Using the OPENSSL_IS_BORINGSSL define
seems better anyway.

URL: https://android.googlesource.com/platform/external/curl/+/f551028d5caab29d4b4a4ae8c159c76c3cfd4887%5E!/
Original-patch-by: Bertrand Simonnet

Closes #393