fix(http-logger): default request path should be '/'

[jiangfucheng]

Description

Fixes #9443

Checklist

• I have explained the need for this PR and the problem it solves
• I have explained the changes or the new features added to this PR
• I have added tests corresponding to this change
• I have updated the documentation to reflect this change
• I have verified that this change is backward compatible (If not, please discuss on the APISIX mailing list first)

[soulbird]

Look at this: https://github.com/api7/lua-resty-http/blob/master/t/13-default-path.t#L27, the default path is /

[jiangfucheng]

Look at this: https://github.com/api7/lua-resty-http/blob/master/t/13-default-path.t#L27, the default path is /

Thanks for you comment, I roughly took a look, the reqeust() method does not seem to cover this situation, it only covered by request_uri() method.