Small change in Pkg internals in 1.6.2.

[KristofferC]

To handle the upcoming new 1.7 manifest format in 1.6, a backport was made to Pkg that slightly changed the internals.
This caused the tests here to error. The error can be seen in https://s3.amazonaws.com/julialang-reports/nanosoldier/pkgeval/by_hash/6d74a23_vs_dd12291/SymbolServer.1.6.2-pre-257e784638.log.

It should be quite easy to workaround.

[pfitzseb]

Thanks for the headsup!

[fredrikekre]

1.6.2 is out now so would be great to have a fix for this.