SteelSeries dispose fails if not initialized

[RobertBeekman]

The code below calls ResetLeds() which in turn calls StopGame() but that fails because PostJson() has no _baseUrl to work with.

RGB.NET/RGB.NET.Devices.SteelSeries/API/SteelSeriesSDK.cs

Line 86 in 0b76199

 internal static void Dispose() 

[DarthAffe]

This should be fixed in 1cfdeef