config: overwrite HTTPHost in config.toml via cli flag

[yutianwu]

Description

Overwrites HTTPHost in config.toml via cli flag when starting a node.

 ./geth --config ./config.toml --datadir ./node  --cache 8000 --http --http.addr 0.0.0.0 

When starting a node with flag http and http.addr, the config HTTPHost will be overwrite by the flag http.addr.

Rationale

It's reasonable to overwrite the config in config.toml via cli flag.

Example

Start a node with command:

 ./geth --config ./config.toml --datadir ./node  --cache 8000 --http --http.addr 0.0.0.0 

Changes

This pr will allow overwriting HTTPHost in config.toml via cli flag.

[unclezoro]

let us plan it in release v1.1.13.