'show me to the square' fails

## Type of Issue

Select the type of issue:
- [x] Bug report (to report a bug)
- [ ] Feature request (to request an additional feature)
- [ ] Tracker (I am just using this as a tracker)
- [ ] Refactor request
- [ ] Documentation Ask

## Description

Questions like 'show me to the square' or 'where is the square' fails. root cause is from py

## Current Behavior

Error log:

```
2021-02-21 23:21:11,839 [nsp_dialogue_manager.py:274 - get_logical_form() INFO]: Found gt action for "show me to the square"
2021-02-21 23:21:11,849 [nsp_dialogue_manager.py:293 - get_logical_form() INFO]: chat before lemmatization "show me to the square"
2021-02-21 23:21:11,861 [nsp_dialogue_manager.py:296 - get_logical_form() INFO]: chat after lemmatization "show -PRON- to the square"
2021-02-21 23:21:11,861 [nsp_dialogue_manager.py:300 - get_logical_form() INFO]: ttad pre-coref "show -PRON- to the square" -> {'dialogue_type': 'GET_MEMORY', 'filters': {'output': {'attribute': 'LOCATION'}, 'triples': [{'pred_text': 'has_name', 'obj_text': 'square'}]}}
2021-02-21 23:21:11,861 [nsp_dialogue_manager.py:310 - get_logical_form() INFO]: logical form before grammar update "{'dialogue_type': 'GET_MEMORY', 'filters': {'output': {'attribute': 'LOCATION'}, 'triples': [{'pred_text': 'has_name', 'obj_text': 'square'}]}}
2021-02-21 23:21:11,861 [nsp_dialogue_manager.py:311 - get_logical_form() INFO]: logical form after grammar fix "{'dialogue_type': 'GET_MEMORY', 'filters': {'output': {'attribute': 'LOCATION'}, 'triples': [{'pred_text': 'has_name', 'obj_text': 'square'}]}}"
2021-02-21 23:21:11,861 [nsp_dialogue_manager.py:168 - handle_logical_form() INFO]: logical form post-coref "8bf9f748734dd668b1407e01009f5a81ef1495d786a3120a7867cd12344380bb:d091d927a0e0475bb5642af9b6c50c20" -> {'dialogue_type': 'GET_MEMORY', 'filters': {'output': {'attribute': 'LOCATION'}, 'triples': [{'pred_text': 'has_name', 'obj_text': 'square'}]}}
2021-02-21 23:21:11,865 [nsp_dialogue_manager.py:184 - handle_logical_form() INFO]: this model out: {'dialogue_type': 'GET_MEMORY', 'filters': {'output': {'attribute': 'LOCATION'}, 'triples': [{'pred_text': 'has_name', 'obj_text': 'square'}]}}
2021-02-21 23:21:11,866 [get_memory_handler.py:172 - do_answer() ERROR]: list index out of range
Traceback (most recent call last):
File "/private/home/yuxuans/Workspace/tmp/droidlet/craftassist/agent/../../base_agent/dialogue_objects/get_memory_handler.py", line 163, in do_answer
target = self.subinterpret["point_target"].point_to_region(vals[0])
IndexError: list index out of range
2021-02-21 23:21:11,869 [craftassist_agent.py:242 - send_chat() INFO]: Sending chat: I don't understand what you're asking
```