Update displayhook.py

Updated to catch IndexError

IPython/core/displayhook.py

@@ -89,6 +89,7 b' class DisplayHook(Configurable):'
         sio = io.StringIO(cell)
         tokens = list(tokenize.generate_tokens(sio.readline))
 
+        try:
     	for token in reversed(tokens):
             if token.type in (tokenize.ENDMARKER, tokenize.COMMENT):
             	continue
@@ -96,6 +97,9 b' class DisplayHook(Configurable):'
             	return True
             else:
             	return False
+        except IndexError:
+            # some uses of ipshellembed may fail here
+            return False
 
     def start_displayhook(self):
         """Start the displayhook, initializing resources."""