Incorrect EC key size defaults to 256bits

[KostasTsiounis]

In the ECKey.generate(int numbits), where the key size is provided as a parameter, if the key is not in [192, 224, 256, 384, 521], secp256r1 is used as the default curve without any indication. In this scenario, I feel a more appropriate action would be to throw an exception.

See line

OpenJCEPlus/src/main/native/ECKey.c

Line 94 in 3b3477a

curveidx = 2;