Add DTLS to SSL_get_version (Imported from upstream's 504e643e0996fb842ac183023c3a6b9049af50ea) Change-Id: I94f4fea105b6eeb001d376ca3ffef77d1432aa88 Reviewed-on: https://boringssl-review.googlesource.com/4462 Reviewed-by: Adam Langley <agl@google.com>