Remove CoreFX configuration.props in tarball build (#686)

(cherry picked from commit 2bb25fc)

Author: dagood

build-source-tarball.sh

@@ -103,6 +103,9 @@ rm -f $TARBALL_ROOT/Tools/dotnetcli/dotnet.tar
 rm -f $TARBALL_ROOT/Tools/dotnetcli/sdk/$SDK_VERSION/nuGetPackagesArchive.lzma
 rm -rf $TARBALL_ROOT/Tools/dotnetcli/store
 rm -rf $TARBALL_ROOT/Tools/dotnetcli/additionalDeps
+# Remove props file generated by CoreFX that contains the RuntimeOS value of the current machine.
+# It artificially limits the tarball to be buildable on only the OS that created it.
+rm -rf $TARBALL_ROOT/Tools/configuration/configuration.props
 
 cp $SCRIPT_ROOT/support/tarball/build.sh $TARBALL_ROOT/build.sh