Stop the build from stepping on its own toes

This line caused every NuGet.Build.Packages.Tasks build after the first
to fail, because it deleted the files needed to build the package a second
time.

Author: wjk

src/Directory.Build.targets

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
 
 	<PropertyGroup>
@@ -60,8 +60,6 @@ AssemblyVersion=$(AssemblyVersion)" />
 	</Target>
 
 	<Target Name="LocalPublish" Condition="'$(CI)' != 'true'" AfterTargets="Pack">
-		<Exec Command='rd "$(NuGetPackageRoot)$(PackageId.ToLowerInvariant())" /q /s' Condition="Exists('$(NuGetPackageRoot)$(PackageId.ToLowerInvariant())')" />
-
 		<ItemGroup>
 			<ToDelete Include="$(TEMP)\packages\$(PackageId)*.nupkg" />
 		</ItemGroup>