[Windows docker] vswitch name wildcard

Got the following logs:

WARN[2018-08-17T10:33:01-07:00] Keystone variable empty: Os_token
INFO[2018-08-17T10:33:15-07:00] Inspecting Hyper-V Extension for property: Running
DEBU[2018-08-17T10:33:15-07:00] Running powershell: -NonInteractive Get-VMSwitchExtension -VMSwitchName "Layered?Ethernet1" -Name "vRouter forwarding extension" | Select -Expand "Running".
DEBU[2018-08-17T10:33:32-07:00] Inspect result:
ERRO[2018-08-17T10:33:32-07:00] Before trying to initialize vRouter: Extension is stopped, when it should be running - possible fix involves reinstallation of the vRouter Forwarding Extension

Inspect result is nil, when it should probably error like "vswitch was not found". This is probably due to passing a vswitch name containing a wildcard - powershell ignores errors then and acts like a dumb filter.