Update GetYubikey.cs

Improved error message.

Author: JMarkstrom

Module/Cmdlets/Yubikey/GetYubikey.cs

@@ -64,8 +64,8 @@ protected override void ProcessRecord()
             }
             else
             {
-                WriteError(new ErrorRecord(new Exception("None YubiKeys selected, Use Connect-Yubikey to specify which Yubikey to use."), "0x00020001", ErrorCategory.InvalidResult, null));
+                WriteError(new ErrorRecord(new Exception("No YubiKey(s) selected, Use Connect-Yubikey to specify which Yubikey to use."), "0x00020001", ErrorCategory.InvalidResult, null));
             }
         }
     }
-}
+}