#234 Build failure with libressl >= 2.5.0

[Fabrice Fontaine]

The build raises the following build failure with libressl > 2.5.0:

crypto/openssl/rsa.c:43:1: error: static declaration of 'RSA_set0_key' follows non-static declaration
43 | RSA_set0_key(RSA r, BIGNUM n, BIGNUM e, BIGNUM d)
| ^~~~~~~~~~~~

Fixes:

• http://autobuild.buildroot.org/results/607131255453da2dc0dab20a24264b3e74001525

[Fabrice Fontaine]

Duplicate of https://sourceforge.net/p/trousers/bugs/222/ so this one should be closed