message: RelEng: Teach ServicingPipeline to infer the version if it's null
  ```
  % .\tools\ReleaseEngineering\ServicingPipeline.ps1
  Inferred servicing version 1.14
  PICK Remove the fallback to wsl.exe when HKCU\...\Lxss doesn't exist
  OK
  ```
diff: @@ -61,6 +61,17 @@ Function Reject() {
  $Host.ExitNestedPrompt()
  }
  +If ([String]::IsNullOrEmpty($Version)) {
  + $BranchVersionRegex = [Regex]"^release-(\d+(\.\d+)+)$"
  + $Branch = & git rev-parse --abbrev-ref HEAD
  + $Version = $BranchVersionRegex.Match($Branch).Groups[1].Value
  + If ([String]::IsNullOrEmpty($Version)) {
  + Write-Error "No version specified, and we can't infer it from the name of your branch ($Branch)."
  + Exit 1
  + }
  + Write-Host "Inferred servicing version $Version"
  +}
  +
  $Script:TodoColumnName = "To Cherry Pick"
  $Script:DoneColumnName = "Cherry Picked"
  $Script:RejectColumnName = "Rejected"
  