Metalhead IJulia notebook broken

@xorJane
vgg = VGG19()
gives an error

EOFError: read end of file

Stacktrace:
  [1] read(s::IOStream, #unused#::Type{UInt8})
    @ Base ./iostream.jl:399
  [2] read
    @ ./Enums.jl:22 [inlined]
  [3] parse_doc(io::IOStream)
    @ BSON ~/.julia/packages/BSON/XAts7/src/read.jl:51
  [4] parse_tag(io::IOStream, tag::BSON.BSONType)
    @ BSON ~/.julia/packages/BSON/XAts7/src/read.jl:15
  [5] parse_doc(io::IOStream)
    @ BSON ~/.julia/packages/BSON/XAts7/src/read.jl:53
  [6] parse
    @ ~/.julia/packages/BSON/XAts7/src/read.jl:101 [inlined]
  [7] open(f::typeof(BSON.parse), args::String; kwargs::Base.Iterators.Pairs{Union{}, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
    @ Base ./io.jl:330
  [8] open
    @ ./io.jl:328 [inlined]
  [9] parse
    @ ~/.julia/packages/BSON/XAts7/src/read.jl:102 [inlined]
 [10] load
    @ ~/.julia/packages/BSON/XAts7/src/read.jl:104 [inlined]
 [11] weights(name::String)
    @ Metalhead ~/.julia/packages/Metalhead/qsJ7m/src/utils.jl:21
 [12] vgg19_layers()
    @ Metalhead ~/.julia/packages/Metalhead/qsJ7m/src/vgg19.jl:2
 [13] VGG19()
    @ Metalhead ~/.julia/packages/Metalhead/qsJ7m/src/vgg19.jl:39
 [14] top-level scope
    @ In[5]:1
 [15] eval
    @ ./boot.jl:360 [inlined]
 [16] include_string(mapexpr::typeof(REPL.softscope), mod::Module, code::String, filename::String)
    @ Base ./loading.jl:1090

on Julia 1.6beta with Metalhead 0.5.1

Reproduce VGG19() in the affected IJulia notebook using Julia 1.6beta and Metalhead 0.5.1. Start with the weights call in utils.jl and the VGG19 paths shown in vgg19.jl; done means constructing VGG19 no longer raises the reported EOFError.