vtr example trailing whitespace

[boriskaus]

here a file that caused earlier versions of ReadVTK to fail.

julia> vtk_read = VTKFile("Convection.vtr");
julia> point_data = get_point_data(vtk_read);
julia> get_data_reshaped(point_data[point_data.names[9]]);
ERROR: BoundsError: attempt to access 738759-element Vector{UInt8} at index [671681:738760]
Stacktrace:
 [1] throw_boundserror(A::Vector{UInt8}, I::Tuple{UnitRange{Int64}})
   @ Base ./abstractarray.jl:703
 [2] checkbounds
   @ ./abstractarray.jl:668 [inlined]
 [3] view
   @ ./subarray.jl:177 [inlined]
 [4] get_data(data_array::VTKDataArray{Float32, 1, ReadVTK.FormatAppended})
   @ ReadVTK ~/Downloads/ReadVTK.jl/src/ReadVTK.jl:756
 [5] #get_data_reshaped#5
   @ ~/Downloads/ReadVTK.jl/src/ReadVTK.jl:792 [inlined]
 [6] get_data_reshaped(data_array::VTKDataArray{Float32, 1, ReadVTK.FormatAppended})
   @ ReadVTK ~/Downloads/ReadVTK.jl/src/ReadVTK.jl:791
 [7] top-level scope
   @ REPL[11]:1