Maybe keep old set_subscribe_callback API behavior in upcoming release

[abitmore]

For better performance on API servers, with #725 we introduced a new enable-subscribe-to-all option to the application, by default disabled, which means API clients (E.G. wallets) will be unable to subscribe to universal object creation and removal events by default.

However, as discussed in bitshares/bitshares-ui#1338, currently the reference wallet does subscribe to universal object creation and removal events. It may need some time for them to change, so we may need to keep the old behavior for longer time to avoid breaking things.

Note: we still want to change the default behavior in the future. So I think the best solution now is to

• temporarily remove the new enable-subscribe-to-all option from configuration_file_options, and
• set default value of application_options::enable_subscribe_to_all to true.

If this change is done, we need to create another ticket (issue) for reverting it in the future.

[abitmore]

PR# 743 merged, closing.