Make data manager thread safe (fix #1808)
Make data manager thread safe (fix #1808)

tsmgeek/traccar,orcoliver/traccar,stalien/traccar_test,tsmgeek/traccar,5of9/traccar,ninioe/traccar,orcoliver/traccar,al3x1s/traccar,stalien/traccar_test,renaudallard/traccar,duke2906/traccar,jon-stumpf/traccar,orcoliver/traccar,AnshulJain1985/Roadcast-Tracker,jssenyange/traccar,AnshulJain1985/Roadcast-Tracker,jssenyange/traccar,jon-stumpf/traccar,ninioe/traccar,tananaev/traccar,ninioe/traccar,jon-stumpf/traccar,tsmgeek/traccar,al3x1s/traccar,duke2906/traccar,jssenyange/traccar,vipien/traccar,tananaev/traccar,joseant/traccar-1,vipien/traccar,5of9/traccar,joseant/traccar-1,tananaev/traccar,renaudallard/traccar