[ruby/openssl] pkey: use unsigned type for bit fields
clang generates a warning:
../../../../ext/openssl/ossl_pkey.c:326:22: error: implicit truncation from 'int' to a one-bit wide bit-field changes value from 1 to -1 [-Werror,-Wsingle-bit-bitfield-constant-conversion] arg->interrupted = 1; ^ ~ 1 error generated.
[ruby/openssl] pkey: use unsigned type for bit fields
clang generates a warning:
https://github.com/ruby/openssl/commit/4b2ba7b022