Copy Paste error in AsyncGuidance.md

[gakera]

Not sure what a better header text would be, but "❌ BAD This example uses Task.Result to get the connection in the constructor. This could lead to thread-pool starvation and deadlocks." is copy pasted in this section: https://github.com/davidfowl/AspNetCoreDiagnosticScenarios/blob/master/AsyncGuidance.md#windowsidentityrunimpersonated

from this section: https://github.com/davidfowl/AspNetCoreDiagnosticScenarios/blob/master/AsyncGuidance.md#constructors

and the context doesn't make sense.