ecore/thread: flush main loop threads during ecore_thread_wait()

this avoids the case where the main loop is waiting on a thread
and that same thread is waiting on the main loop

@fix

Differential Revision: https://phab.enlightenment.org/D6438

src/lib/ecore/ecore_thread.c

@@ -869,7 +869,8 @@ ecore_thread_wait(Ecore_Thread *thread, double wait)
         double start, end;
 
         start = ecore_time_get();
-        ecore_main_loop_thread_safe_call_wait(wait);
+        _ecore_main_call_flush();
+        ecore_main_loop_thread_safe_call_wait(0.0001);
         end = ecore_time_get();
 
         wait -= end - start;