fix(jupyter): adopted to support more formats. Fixes: RCCE-38

rhodecode/lib/markup_renderer.py

@@ -449,7 +449,7 b' class MarkupRenderer(object):'
                     cell.source = cls.sanitize_html(cell.source)
                     return cell, resources
 
-                for cell_output in cell.outputs:
+                for cell_output in cell.get('outputs', []):
                     if 'data' in cell_output:
                         if 'application/javascript' in cell_output['data']:
                             cell_output['data']['text/plain'] = sandbox_text
@@ -553,7 +553,7 b' class MarkupRenderer(object):'
         else:
             try:
                 body, _ = as_html(notebook)
-            except AttributeError:
+            except (AttributeError, nbformat.ValidationError):
                 try:
                     nbformat.validate(nbformat.reader.reads(source))
                 except nbformat.ValidationError as exc: