Merge pull request #673 from marcoamonteiro/keyboard-interrupt-handler

fix keyboard interrupt issue in dispatch_shell

Author: blink1073

ipykernel/kernelbase.py

@@ -352,6 +352,9 @@ async def dispatch_shell(self, msg):
                     await result
             except Exception:
                 self.log.error("Exception in message handler:", exc_info=True)
+            except KeyboardInterrupt:
+                # Ctrl-c shouldn't crash the kernel here.
+                self.log.error("KeyboardInterrupt caught in kernel.")	
             finally:
                 try:
                     self.post_handler_hook()