fix: HTTP/1 active-request metrics leak when response ends before request body completes

[waterWang]

Fix HTTP/1 active-request metrics leak when connection closes before request body completes

Problem

When an HTTP/1 server ends the response before the request body has fully arrived, and the client then closes the connection without completing the declared body, Micrometer receives requestBegin and responseEnd, but neither requestEnd nor requestReset. The vertx_http_server_active_requests gauge therefore retains the request forever, increasing monotonically with each connection.

Example: a client sends GET / with Content-Length: 1, the server responds 401 early, the client closes without sending the byte.

Root cause

Http1ServerConnection.handleClosed() only cleans up metrics for responseInProgress (via handleException), but when the response has already been sent the responseInProgress field is null. The requestInProgress still references the request whose body never completed (requestEnd was never reported), and when the connection closes the request metric is never reset.

Fix

In handleClosed(), after handling responseInProgress, also report requestReset on requestInProgress when:

• it is a different request from responseInProgress
• its body did not complete (!isEnded())

This matches the existing metric invariants: every requestBegin must be paired with exactly one terminal event (requestEnd or requestReset).

[tsegismont]

Superseded by #6336