Add IndexError to catch expression when calculating transcription con…

…fidence -- in case when there are no logits (i.e. logits.shape[0] == 0) the confidence cannot be calculated.

pero_ocr/document_ocr/page_parser.py

@@ -587,7 +587,7 @@ def get_line_confidence(self, line):
                 log_probs = line.get_full_logprobs()[line.logit_coords[0]:line.logit_coords[1]]
                 confidences = get_line_confidence(line, log_probs=log_probs)
                 return np.quantile(confidences, .50)
-            except ValueError as e:
+            except (ValueError, IndexError) as e:
                 logger.warning(f'PageOCR is unable to get confidence of line {line.id} due to exception: {e}.')
                 return self.default_confidence
         return self.default_confidence