message: Update error message for non-standard primitives.
diff: #include "tink/config.h"
  #include "absl/strings/ascii.h"
  +#include "absl/strings/str_cat.h"
  #include "tink/aead/aead_config.h"
  #include "tink/daead/deterministic_aead_config.h"
  #include "tink/hybrid/hybrid_config.h"
  @@ -91,11 +92,12 @@ util::Status Config::Register(
  // everything from the streamingaead config.
  status = StreamingAeadConfig::Register();
  } else {
  - status = ToStatusF(crypto::tink::util::error::INVALID_ARGUMENT,
  - "A non-standard primitive '%s' '%s', "
  - "use directly Config::Register<P>(KeyTypeEntry&).",
  - entry.primitive_name().c_str(),
  - primitive_name.c_str()
  + status = util::Status(crypto::tink::util::error::INVALID_ARGUMENT,
  + absl::StrCat("Non-standard primitive '",
  + entry.primitive_name(),
  + "', call Registry::RegisterKeyManager "
  + "and Registry::"
  + "RegisterPrimitiveWrapper directly.")
  );
  }
  if (!status.ok()) return status;
  