[core] Remove a stray TString::Append that was generating diagnostics.
[core] Remove a stray TString::Append that was generating diagnostics.

olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root