message: fix: don't run verifier if container not defined
diff: @@ -825,7 +825,7 @@ bool Container::verify() const
  verified &= verifyRequired(*m_sidreGroup, this_container_defined, "Container");
  // Verify this Container if a lambda was configured
  - if(m_verifier && !m_verifier(*this))
  + if(this_container_defined && m_verifier && !m_verifier(*this))
  {
  verified = false;
  SLIC_WARNING(
  