Gracefully handle card render fail.

app.py

@@ -214,15 +214,18 @@ def html_to_png(card_name, html):
         css = ['./colab-data-test/css/mana.css', './colab-data-test/css/keyrune.css', './colab-data-test/css/mtg_custom.css']
         imgkit.from_string(html, path, {"xvfb": ""}, css=css)
     except:
-        # For Windows local, requires 'html2image' package from pip.
-        from html2image import Html2Image
-        rendered_card_dir = 'rendered_cards'
-        hti = Html2Image(output_path=rendered_card_dir)
-        paths = hti.screenshot(html_str=html,
-                               css_file=['./colab-data-test/css/mtg_custom.css', './colab-data-test/css/mana.css', './colab-data-test/css/keyrune.css'],
-                               save_as=save_name, size=(450, 600))
-        print(paths)
-        path = paths[0]
+        try:
+            # For Windows local, requires 'html2image' package from pip.
+            from html2image import Html2Image
+            rendered_card_dir = 'rendered_cards'
+            hti = Html2Image(output_path=rendered_card_dir)
+            paths = hti.screenshot(html_str=html,
+                                   css_file=['./colab-data-test/css/mtg_custom.css', './colab-data-test/css/mana.css', './colab-data-test/css/keyrune.css'],
+                                   save_as=save_name, size=(450, 600))
+            print(paths)
+            path = paths[0]
+        except:
+            pass
     print('OPENING IMAGE FROM FILE')
     img = Image.open(path)
     print('CROPPING BACKGROUND')