mod_pubsub_serverinfo: Update to use mod_server_info (fixes #1841)
...but only for Prosody trunk users, because 0.12 mod_server_contact_info does
not use the new API in mod_server_info.
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summary: Storage benchmark tool
...
To benchmark `mod_storage_internal`:
prosodyctl mod_benchmark_storage internal
Does a number (aprox. 10000) of reads and writes and to the selected
storage driver and tells you how long it took.