Remove redundant documentation

    pub fn X509_get_pubkey(x: *mut X509) -> *mut EVP_PKEY;

    pub fn X509_set_version(x: *mut X509, version: c_long) -> c_int;

    /// Returns certificate version previously set through `X509_set_version` or the default which

    /// is `0`.

    ///

    /// **Important.** The corresponding OpenSSL method is not expected to fail under its

    /// correct implementation. Despite that, the method invocation passes through scopes which

    /// _may_ result in error. Having that it is encouraged to validate returned value.

    pub fn X509_get_version(x: *const X509) -> c_long;

    pub fn X509_set_serialNumber(x: *mut X509, sn: *mut ASN1_INTEGER) -> c_int;

    pub fn X509_get_serialNumber(x: *mut X509) -> *mut ASN1_INTEGER;