Remove reference to RSA_PKCS1_RSAref, since it doesn't exist any more.

=head1 NAME

RSA_set_default_method, RSA_get_default_method, RSA_set_method,

RSA_get_method, RSA_PKCS1_SSLeay,

RSA_null_method, RSA_flags, RSA_new_method - select RSA method

RSA_get_method, RSA_PKCS1_SSLeay, RSA_null_method, RSA_flags,

RSA_new_method - select RSA method

=head1 SYNOPSIS

 #include <openssl/rsa.h>

 #include <openssl/engine.h>

 void RSA_set_default_method(const RSA_METHOD *meth);

 RSA_METHOD *RSA_PKCS1_SSLeay(void);

 RSA_METHOD *RSA_PKCS1_RSAref(void);

 RSA_METHOD *RSA_null_method(void);

 int RSA_flags(const RSA *rsa);

 RSA *RSA_new_method(ENGINE *engine);

 RSA *RSA_new_method(RSA_METHOD *method);

=head1 DESCRIPTION

default ENGINE for RSA operations is used, and if no default ENGINE is set,

the RSA_METHOD controlled by RSA_set_default_method() is used.

RSA_flags() returns the B<flags> that are set for B<rsa>'s current method.

RSA_new_method() allocates and initializes an B<RSA> structure so that

B<method> will be used for the RSA operations. If B<method> is B<NULL>,

the default method is used.

=head1 THE RSA_METHOD STRUCTURE

 typedef struct rsa_meth_st