startup filter gobbles up all exceptions from all pipeline configuration #897

Title covers the problem. This filter should not be catching exceptions from downstream appbuilders. It was very confusing to debug this.

Repro Steps

1. Throw an exception in your Startup class Configure method with App Insights 2.7.0 installed.

Actual Behavior

No exception reaches WebHostBuilder logic

Expected Behavior

Exception propogates out of pipeline configuration

Version Info

Bug was introduced in this commit:
2def166#diff-f48f778899a1b501f8f8c45b35ada34b