Fix crash on row errors

validata_core/__init__.py

@@ -147,7 +147,7 @@ def amend_report(report):
     row_col_set = set()
     for err in errors:
         if err['tag'] == 'value':
-            row_col_id = '{}_{}'.format(err['row-number'], err['column-number'])
+            row_col_id = '{}_{}'.format(err['row-number'], err.get('column-number', ''))
             if row_col_id in row_col_set:
                 continue
             row_col_set.add(row_col_id)