Fix missing '**kwargs' parameters passing to imshow_bboxes() (#6034)
Fix missing '**kwargs' parameters passing to imshow_bboxes() (#6034)

'**kwargs' parameters haven't passed to mmcv.imshow_bboxes() in show_result() of mmdetection/mmdet/models/detectors/rpn.py
open-mmlab/mmdetection,open-mmlab/mmdetection