OF-2524: Add database index for MUC room log retrieval
When loading the MUC room history for a single room, a query is executed that is not optimized by the existing database indexes:
`SELECT sender, nickname, logTime, subject, body, stanza FROM ofMucConversationLog WHERE logTime>? AND roomID=? AND (nickname IS NOT NULL OR subject IS NOT NULL) ORDER BY logTime`
On Ignite's server, this takes more than 400 milliseconds to execute.
When room preloading is disabled, all rooms that are being used need to be loaded from memory. Looking at the admin console will load all rooms on that page. If that contains 25 rooms, then this query alone causes a delay of many seconds before the page is loaded.
OF-2521: Allow SASL EXTERNAL for S2S by default
For SASL EXTERNAL to be used to authenticate server-to-server connections, Java's "client authentication" must be enabled, allowing peer certificates to be processed.
This improves on the changes in OF-1855, which would enable this by default _if_ the local server had a non-selfsigned certificate installed. That condition does not make a lot of sense, as the local certificate does/should not affect the validation of the certificates provided by the peer.