Totara branch throws an exception during shutdown, due to calling "get_session_lock_info()" function that isn't present in Totara prior to 19.1

[agwells]

To replicate:

1. Clean install of Totara (17, 18, or 19) with the plugin from the TOTARA_19 branch
2. Go to admin/settings.php?section=tool_excimer and set "Minimum request duration" to "1"
3. Go to admin/tool/excimer/recent.php

• Expected result: Each page load should be logged
• Actual result:
  • None of the page loads are logged
  • Error log shows message "Exception ignored in shutdown function Closure::__invoke: Call to undefined method core\session\manager::get_session_lock_info()"

The problem is that script_metadata::get_lock_info() tries to call \core\session\manager::get_session_lock_info(), but this function isn't present in Totara. It was added to Moodle after Totara forked away.

The quick fix is to just make script_metadata::get_lock_info() return an empty array, in which case the request is logged without any log info.

Totara 19.1 actually includes this plugin as part of core, and they've patched the session manager to include a get_session_lock_info() function.