Remove needless event2/thread.h include from test_compat_libevent.c

src/test/test_compat_libevent.c

@@ -10,7 +10,6 @@
 #include "compat_libevent.h"
 
 #include <event2/event.h>
-#include <event2/thread.h>
 
 #include "log_test_helpers.h"