Remove bad command (#177)

Author: gsacavdm

WSL/install-on-server.md

@@ -23,7 +23,6 @@ Enable the "Windows Subsystem for Linux" optional feature and reboot.
 
 1. Open PowerShell as Administrator and run:
     ``` PowerShell
-    PowerShell
     Enable-WindowsOptionalFeature -Online -FeatureName Microsoft-Windows-Subsystem-Linux
     ```