Logging app initialization failure using config.log

On exiting due to an unhandled exception during the app initialization (lifespan), the process(es) spawned by `multiprocessing.BaseContext.Process.start()` in `_populate()` would have their stack traceback directly printed to stderr by `BaseProcess:_bootstrap`.

Using the user-configurable `config.log` logger instead makes the log output more consistent.

Author: Pierre Delagrave

src/hypercorn/asyncio/run.py

@@ -84,7 +84,11 @@ def _signal_handler(*_: Any) -> None:  # noqa: N803
     if lifespan_task.done():
         exception = lifespan_task.exception()
         if exception is not None:
-            raise exception
+            await config.log.exception(
+                "Error initializing ASGI app",
+                exc_info=(type(exception), exception, exception .__traceback__)
+            )
+            exit(1)
 
     if sockets is None:
         sockets = config.create_sockets()