Validate NetAnalyzers offline only

Author: ViktorHofer

src/Microsoft.CodeAnalysis.NetAnalyzers/src/Microsoft.CodeAnalysis.NetAnalyzers.Package.csproj

@@ -82,7 +82,9 @@
 
       <!-- Validate offline in .NET product build mode. -->
       <_ValidateOffline Condition="'$(DotNetBuild)' == 'true'">true</_ValidateOffline>
-      <_ValidateOffline Condition="'$(_ValidateOffline)' == ''">false</_ValidateOffline>
+
+      <!-- AuthenticationException: The remote certificate is invalid because of errors in the certificate chain: RevocationStatusUnknown -->
+      <_ValidateOffline Condition="'$(_ValidateOffline)' == ''">true</_ValidateOffline>
 
       <_GenerateDocumentationAndConfigFilesPath>%(_GenerateDocumentationAndConfigFilesPath.Identity)</_GenerateDocumentationAndConfigFilesPath>
     </PropertyGroup>