make cython app exit correctly

Azaion.Inference/inference.pyx

@@ -137,7 +137,7 @@ cdef class Inference:
         self._previous_annotation = None
 
         v_input = cv2.VideoCapture(<str>video_name)
-        while v_input.isOpened():
+        while v_input.isOpened() and not self.stop_signal:
             ret, frame = v_input.read()
             if not ret or frame is None:
                 break
@@ -186,11 +186,9 @@ cdef class Inference:
             print(annotation.to_str(self.class_names))
             self.on_annotation(cmd, annotation)
 
-
     cdef stop(self):
         self.stop_signal = True
 
-
     cdef bint is_valid_annotation(self, Annotation annotation):
         # No detections, invalid
         if not annotation.detections: