Package nuspec only contains a deprecated licenseUrl

[Corniel]

Please update the NuSpec file of the package, using a <licenseExpression> and a <licenseFile> instead of the <licenseUrl> that has been deprecated for more than 7 years now.

<?xml version="1.0" encoding="utf-8"?>
<package xmlns="http://schemas.microsoft.com/packaging/2013/05/nuspec.xsd">
  <metadata>
    <id>MysticMind.PostgresEmbed</id>
    <version>4.0.0</version>
    <authors>Babu Annamalai</authors>
    <licenseUrl>https://github.com/mysticmind/mysticmind-postgresembed/blob/master/LICENSE</licenseUrl>
    <projectUrl>https://github.com/mysticmind/mysticmind-postgresembed</projectUrl>
    <description>Postgres embedded server equivalent for .Net applications</description>
    <copyright>Copyright (C) Babu Annamalai</copyright>
    <tags>postgres postgresql pg embed embedded server .net 4.6 net 4.6 net46 .net core net core netcore netcore 2.0 netcore rtm</tags>
    <repository type="git" url="https://github.com/mysticmind/mysticmind-postgresembed" commit="3b08c713c4eb415c9c7edece1ca194b40f369835" />
    <dependencies>
      <!-- .. -->
  </metadata>
</package>

See Proj0500: Only include packages with an explicitly defined license