remove line in jetty docs about JDK9 and HTTP2 (#2230)

Signed-off-by: Lachlan Roberts <[email protected]>

jetty/content.md

@@ -90,8 +90,6 @@ RUN java -jar $JETTY_HOME/start.jar --add-to-startd=http2 --approve-all-licenses
 
 This will add an `http2.ini` file to the `$JETTY_BASE/start.d` directory and download the required ALPN libraries into `$JETTY_BASE/lib/alpn`, allowing the use of HTTP/2. HTTP/2 connections should be made via the same port as normal HTTPS connections (container port 8443). If you would like to enable the `http2` module via `$JETTY_BASE/start.ini` instead, substitute `--add-to-start` in place of `--add-to-startd` in the `RUN` command above.
 
-Once OpenJDK 9 becomes generally available with built-in support for ALPN, this image will be updated to enable HTTP/2 support by default.
-
 # Security
 
 By default, this image starts as user `root` and uses Jetty's `setuid` module to drop privileges to user `jetty` after initialization. The `JETTY_BASE` directory at `/var/lib/jetty` is owned by `jetty:jetty` (uid 999, gid 999).