Fails to read 4 instances from Maros-Meszaros QP benchmark

Here are the four culprits, diagnosed with [MathOptBenchmarkInstances.jl](https://github.com/JuliaDecisionFocusedLearning/MathOptBenchmarkInstances.jl) (soon to be registered):

```julia
julia> using MathOptBenchmarkInstances

julia> for name in ["EXDATA", "QFORPLAN", "QGFRDXPN", "VALUES"]
@info name
try
read_instance(MarosMeszaros, name)
catch e
@show e
end
end
[ Info: EXDATA
e = ErrorException("Unknown column -10.")
[ Info: QFORPLAN
e = ErrorException("Duplicate row name DEDO3 at line 6")
[ Info: QGFRDXPN
e = ArgumentError("cannot parse \"PEE\" as Float64")
[ Info: VALUES
e = ErrorException("Unknown column 10.")
```