Creating and verifying RSA signatures requires some OpenSSL functions
declared in the `openssl/rsa.h` header. When `OPENSSL_NO_DEPRECATED` is
not defined this header gets indirectly included. But with this define
set the function declarations are missing. This commit adds an explicit
include for the file to fix this.

Some functions from OpenSSL redefined in `OpenSSLErrorTest.cpp` use
types that are not available when `OPENSSL_NO_DEPRECATED` is defined.
Since they do not seem to be actually used this commit simply removes
them.