Fix #885 RESTler did not honor --time_budget (#889)

Move the timeout check so it is checked on every rendering.

Testing:
- manual testing

restler/engine/core/sequences.py

@@ -581,6 +581,10 @@ def copy_self():
                 request.render_iter(candidate_values_pool,
                                     skip=request._current_combination_id,
                                     preprocessing=preprocessing):
+
+            if Monitor().remaining_time_budget <= 0 and not postprocessing:
+                raise TimeOutException("Exceeded Timeout")
+
             # Hold the lock (because other workers may be rendering the same
             # request) and check whether the current rendering is known from the
             # past to lead to invalid status codes. If so, skip the current
@@ -665,9 +669,6 @@ def copy_self():
             if lock is not None:
                 lock.release()
 
-            if Monitor().remaining_time_budget <= 0 and not postprocessing:
-                raise TimeOutException("Exceeded Timeout")
-
             if lock is not None:
                 lock.acquire()
             # Deep  copying here will try copying anything the class has access