ZeroOrMore can only handle one URL

Python 3.10, pyparsing 3.0.9:

```
print(pp.common.url[...].parse_string('http://foo.com'))
# ['http://foo.com']

print(pp.common.url[...].parse_string('http://bar.com'))
# ['http://bar.com']

print(pp.common.url[...].parse_string('http://foo.com http://bar.com'))
# []
```