doc: fix 'aborted' event documentation

The `'aborted'` event is only emitted on `http.IncomingMessage`
instances.

PR-URL: https://github.com/nodejs/node/pull/15471
Fixes: https://github.com/nodejs/node/issues/15259
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Minwoo Jung <minwoo@nodesource.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Franziska Hinkelmann <franziska.hinkelmann@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

doc/api/http.md

@@ -284,14 +284,6 @@ added: v1.4.1
 Emitted when the request has been aborted by the client. This event is only
 emitted on the first call to `abort()`.
 
-### Event: 'aborted'
-<!-- YAML
-added: v0.3.8
--->
-
-Emitted when the request has been aborted by the server and the network
-socket has closed.
-
 ### Event: 'connect'
 <!-- YAML
 added: v0.7.0
@@ -1196,8 +1188,7 @@ following additional events, methods, and properties.
 added: v0.3.8
 -->
 
-Emitted when the request has been aborted by the client and the network
-socket has closed.
+Emitted when the request has been aborted and the network socket has closed.
 
 ### Event: 'close'
 <!-- YAML