Rathole config watcher doesn't work with symlinks

[yashgorana]

Describe the bug
When config files are symlinks, rathole won't pickup any changes file pointed to by the symlink. This is needed to detect any changes that are made to a Kubernetes ConfigMap mounted to a rathole pod at a path.

To Reproduce
Steps to reproduce the behavior:

1. Create a test/config.toml
2. Create a symlink ln -s ./test/config.toml ./config.toml
3. Run rathole --server ./config.toml
4. Edit test/config.toml or config.toml to change the server config to bind_addr = "0.0.0.0:1333"
5. Observe changes are not picked up and rathole doesn't hot reload.

Configuration

[server]
bind_addr = "0.0.0.0:2333"

[server.services.domain]
token = "domain-specific-rathole-secret"
bind_addr = "0.0.0.0:8001"

Logs

No hot reload log even after changing the config

$ RUST_BACKTRACE=1 rathole ./server.toml
2024-05-01T13:34:09.659589Z  INFO rathole::server: Listening at 0.0.0.0:2333
2024-05-01T13:34:09.659660Z  INFO config_watcher{path="./server.toml"}: rathole::config_watcher: Start watching the config

Environment:

• OS: Linux Container, Kubernetes
• rathole --version output:

rathole
Build Timestamp:     2023-10-01T10:08:07.162273634Z
Build Version:       0.5.0
Commit SHA:          None
Commit Date:         None
Commit Branch:       None
cargo Target Triple: x86_64-unknown-linux-gnu
cargo Profile:       release
cargo Features:      base64,client,default,futures_core,futures_sink,hot_reload,noise,notify,server,snowstorm,tls,tokio_native_tls,tokio_tungstenite,tokio_util,websocket

• CPU architecture: amd64
• rustc version: N/A

[Bubbleioa]

Just change this line.
Bubbleioa@5017970