demo keystore is no longer copied to jetty-base when enabling ssl

[lachlan-roberts]

In jetty-9.4.x we copy a demo keystore file with a self signed certificate to jetty-base when ssl is enabled, this is not being done in jetty-10.0.x.

The documentation for both 9 & 10 says:

Note that the HTTPS module downloads a demo keystore file with a self signed certificate, which needs to be replaced by a Certificate Authority issued certificate for real deployment.

[lachlan-roberts]

This may have been done for reasons described in #1673.

[lachlan-roberts]

@WalkerWatch we have a test-keystore module in jetty-10 which sets up this demo keystore, this was done by the ssl module in jetty-9. We should mention this in the jetty-10 docs.

To use SSL they will now need to configure their own keystore with ssl.mod or explicitly enable the test-keystore module.