compile error when try to run install command for influxdb v1.9.2

__Steps to reproduce:__
follow the instruction of running install command for compiling influxdb v1.9.2

__Expected behavior:__
successfully compiled

__Actual behavior:__
report compile error

__Environment info:__
System info: Linux 4.18.0-147.5.1.6.h451.eulerosv2r9.x86_64 x86_64
InfluxDB version: v1.9.2

__Logs:__
compiling flux-core v0.4.0 (...)
error: field is never read: 'message'
--> flux-core/src/parser/mod.rs:35:5
pub message: String,
note: the lint level is defined here
-->flux-core/src/lib.rs:1:38
#![cfg_attr(feature = "strict", deny(warnings, missing_docs))]

__Performance:__
When follow the instruction of running install command for compiling influxdb v1.9.2, an compiling error will show up. this error is about the lint for Rust. There is a line of code pub message: String, in this path: flux-core/src/parser/mod.rs:35:5 will produce a lint warning. Although warning alone will not stop the compiling progress. However, there is another command #![cfg_attr(feature = "strict", deny(warnings, missing_docs))] in path flux-core/src/lib.rs:1:38 that will make the warnings to be error and the error will interupt and fail the compiling progress. Based on my own test, if I delete the code #![cfg_attr(feature = "strict", deny(warnings, missing_docs))], the compile progress will be successful.

Reproduce the install command for InfluxDB v1.9.2 on the reported Linux environment. Inspect flux-core/src/parser/mod.rs around the unused message field and flux-core/src/lib.rs around the strict warning lint, then verify the install command compiles successfully without regressions.

Written by the indexing model from the issue text.