trying -sfp2 option on 7z for appveyor

Tools/zip_files.ps1

@@ -68,8 +68,8 @@ if ($ConfigurationName -eq "Release Portable") {
     # AppVeyor build
     if(!([string]::IsNullOrEmpty($Env:APPVEYOR_BUILD_FOLDER))) {
         $outputZipPath = Join-Path -Path $SolutionDir -ChildPath "Release\mRemoteNG-Portable-$($version).zip"
-        #7z a -spf $outputZipPath $Source
-        7z a -bt -bd -bb1 -mx=9 -tzip -y -r $PortableZip "$($Source)"
+        7z a -spf2 $outputZipPath $Source
+        #7z a -bt -bd -bb1 -mx=9 -tzip -y -r $PortableZip "$($Source)"
     }
     # Local build
     else {