doc: fix typo in zlib.md

Change 'methods with throw an error' to 'methods will throw an error'.

PR-URL: nodejs#9123
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Teddy Katz <teddy.katz@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Brian White <mscdex@mscdex.net>

doc/api/zlib.md

@@ -113,7 +113,7 @@ http.createServer((request, response) => {
 }).listen(1337);
 ```
 
-By default, the `zlib` methods with throw an error when decompressing
+By default, the `zlib` methods will throw an error when decompressing
 truncated data. However, if it is known that the data is incomplete, or
 the desire is to inspect only the beginning of a compressed file, it is
 possible to suppress the default error handling by changing the flushing