`get` error with NLSModels

The definition of the getter https://github.com/JuliaSmoothOptimizers/NLPModels.jl/blob/main/src/nls/tools.jl is overloading the classical getter. So, we get:
```
julia> using NLPModels, NLPModelsTest

julia> nlp = LLS();

julia> (nlp.meta.nnzh, nlp.nls_meta.nnzh)
(2, 0)

julia> get_nnzh(nlp)
0

julia> nlp = NLSLC();

julia> (nlp.meta.nnzh, nlp.nls_meta.nnzh)
(120, 15)

julia> get_nnzh(nlp)
15
```

This is the error here https://github.com/JuliaSmoothOptimizers/NLPModelsTest.jl/pull/60