Process latency count more carefully

[DifferentialOrange]

If user forgets to return correct response object in HTTP handler, it results in "trying to subscribe nil" error in this line:

metrics/metrics/http_middleware.lua

Line 75 in a2d783e

status = (not ok and 500) or result.status or 200,

We should process this more carefully. For example, throw explicit error("incorrect http handler").

[github-actions]

This issue is stale because it has been open 60 days with no activity. Remove stale label or comment or this will be closed in 30 days

[DifferentialOrange]

Still relevant, I stepped on this mine once again in Monday

[github-actions]

This issue is stale because it has been open 60 days with no activity. Remove stale label or comment or this will be closed in 30 days