Update error message to distinguish tree revocation issue from non-tree
Update error message to distinguish tree revocation issue from non-tree

rnaveiras/vault,tallpauley/vault,joelthompson/vault,mgk/vault,Aloomaio/vault,kingland/vault,quixoten/vault,wjam/vault,hartsock/vault,lemondrank/vault,hashicorp/vault,lirao/vault,hartsock/vault,deverton/hashicorp-vault,MonsantoCo/vault,wjam/vault,hashicorp/vault,rnaveiras/vault,deverton/hashicorp-vault,hashicorp/vault,tallpauley/vault,joelthompson/vault,quixoten/vault,kingland/vault,naunga/vault,Aloomaio/vault,rnaveiras/vault,kingland/vault,Caiyeon/vault,lemondrank/vault,hartsock/vault,Caiyeon/vault,kingland/vault,hashicorp/vault,mgk/vault,hartsock/vault,joelthompson/vault,joelthompson/vault,hashicorp/vault,hashicorp/vault,ryon/vault,rnaveiras/vault,hartsock/vault,MonsantoCo/vault,rnaveiras/vault,Aloomaio/vault,lirao/vault,naunga/vault,kingland/vault,quixoten/vault,mgk/vault,Aloomaio/vault,ryon/vault,quixoten/vault,mgk/vault