add signaal for export step

source/recorder.py

 
 def handler(signal, frame):
     global stop_signal
-    global zed_list
-    stop_signal = True    
+    global zed_list        
+    stop_signal = True
     time.sleep(2)
     exit()
 
             frame_list[index] += 1
 
     zed_list[index].disable_recording()
+    
+    filepath = '%s/log.txt'%(target_dir)
+    f = open(filepath, 'w')
+    f.write('record succesfully stopped')
+    f.close()
     #print('saved')    
 
 def main():