doc: clarify http.get data consumption requirement

With the previous wording, I read this sentence as meaning, "you
_must_ use the http.get callback mechanism and cannot register a
listener on the returned http.ClientRequest object." This is obviously
not the intention, so adjust the sentence to make this clearer.

PR-URL: nodejs/node#15049
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

doc/api/http.md

@@ -1695,8 +1695,8 @@ changes:
 Since most requests are GET requests without bodies, Node.js provides this
 convenience method. The only difference between this method and
 [`http.request()`][] is that it sets the method to GET and calls `req.end()`
-automatically. Note that response data must be consumed in the callback
-for reasons stated in [`http.ClientRequest`][] section.
+automatically. Note that the callback must take care to consume the response
+data for reasons stated in [`http.ClientRequest`][] section.
 
 The `callback` is invoked with a single argument that is an instance of
 [`http.IncomingMessage`][]