"Dotnet restore" fails on .netstandard projects under 1.6 #2243

dotnet restore {SolutionFile} fails when we have a .netstandard project that triggers versions 1.0-1.5

Repro steps

Please provide the steps required to reproduce the problem

1. cd to PaketRepro folder
2. dotnet restore .\PaketRepro.sln --you should see it ok, is missing from the csproj
3. git checkout 0e599fd399af05345b5425d41152a91149beb315 --force
4. dotnet restore .\PaketRepro.sln --you should see it fails now, the import is preset.
   PaketRepro.zip

Expected behavior

When running "dotnet restore {SolutionFile}" runs we should not get an error.

Actual behavior

C:\Program Files\dotnet\sdk\1.0.2\NuGet.targets(97,5): error : Package System.Security.Cryptography.OpenSsl 4.3.0 is not
compatible with netstandard1.3 (.NETStandard,Version=v1.3). Package System.Security.Cryptography.OpenSsl 4.3.0 supports
: netstandard1.6 (.NETStandard,Version=v1.6) [D:\ticket\1373\PaketRepro\PaketRepro.sln]
C:\Program Files\dotnet\sdk\1.0.2\NuGet.targets(97,5): error : One or more packages are incompatible with .NETStandard,V
ersion=v1.3. [D:\ticket\1373\PaketRepro\PaketRepro.sln]

Known workarounds

Remove the import, but not sure if it is ok.