Superfluous self in optiflow/gst_wrapper.py leading to AttributeError

[grolysaini]

In line 76 of optiflow/gst_wrapper.py self.bus.timed_pop_filtered should be bus.timed_pop_filtered as there is no self.bus in the code.
The error thrown is

Traceback (most recent call last):
  File "/opt/edgeai-gst-apps/optiflow/optiflow.py", line 68, in <module>
    main(sys.argv)
  File "/opt/edgeai-gst-apps/optiflow/optiflow.py", line 49, in main
    optiflow.run()
  File "/opt/edgeai-gst-apps/optiflow/optiflow_class.py", line 175, in run
    self.gst_pipe.run()
  File "/opt/edgeai-gst-apps/optiflow/gst_wrapper.py", line 76, in run
    msg = self.bus.timed_pop_filtered(Gst.CLOCK_TIME_NONE, Gst.MessageType.ERROR)
          ^^^^^^^^
AttributeError: 'GstPipe' object has no attribute 'bus' 

after correction the actual pipeline bus error is shown correctly.