[BUG] Race condition when updating the last sync date/time causes automatic updates to be mistaken for user changes #598

Essentially, this is a race condition that occurs when Emby Next Gen updates its own “last sync date/time.” The date and time are written separately, and the listener thread may read them in between the two writes, resulting in an inconsistent value. It then mistakenly interprets the plugin’s own automatic update as a manual change made by the user, then leads to a full sync!