ParseError from specific utterances

[krisgesling]

Describe the bug
Certain utterances result in ParseError

To Reproduce

1. "Hey Mycroft, what is four score and seven years ago"
2. See error:

2021-04-28 01:45:30.463 | ERROR | 804 | mycroft.skills.mycroft_skill.mycroft_skill:on_error:835 | An error occurred while processing a request in Duckduckgo Skill
Traceback (most recent call last):
File “/home/pi/mycroft-core/mycroft/skills/mycroft_skill/event_container.py”, line 66, in wrapper
handler(message)
File “/home/pi/mycroft-core/mycroft/skills/common_query_skill.py”, line 76, in __handle_question_query
result = self.CQS_match_query_phrase(search_phrase)
File “/opt/mycroft/skills/mycroft-fallback-duck-duck-go.mycroftai/init.py”, line 133, in CQS_match_query_phrase
answer = self.respond(query[len(test):])
File “/opt/mycroft/skills/mycroft-fallback-duck-duck-go.mycroftai/init.py”, line 109, in respond
r = ddg.query(query)
File “/home/pi/mycroft-core/.venv/lib/python3.7/site-packages/ddg3.py”, line 29, in query
xml = ElementTree.fromstring(response)
File “/usr/lib/python3.7/xml/etree/ElementTree.py”, line 1315, in XML
parser.feed(text)
File “”, line None

Environment (please complete the following information):

• Device type: Mark II
• Mycroft-core version: 20.8.1
• Mycroft container: 2021-04-08

Thanks to Wallyllama for reporting this.