Rename DrainNGenQueue.ps to DrainNGenQueue.ps1 (#768)

to actually make this a PowerShell Script as .ps is not an accepted PowerShell Script extension

tools/DrainNGENQueue/DrainNGenQueue.ps1

@@ -36,4 +36,4 @@ if ($isWin8Plus) {
 if ($isWin8Plus -and $is64Bit) {
     Write-Host("Requesting 64-bit AutoNGEN -- Windows 8+") 
     schTasks /run /Tn "\Microsoft\Windows\.NET Framework\.NET Framework NGEN v4.0.30319 64"
-}
+}