cli: Default to "config.toml" as config file

This is expected to run through a systemd system service, with the
config file explicitly specified. Using XDG for the default config makes
little sense in that case, and ends up causing issues with a strict
systemd service file.

Signed-off-by: Gergely Nagy <me@gergo.csillger.hu>

Cargo.lock

@@ -765,7 +765,6 @@ dependencies = [
  "tower-http",
  "tracing",
  "tracing-subscriber",
- "xdg",
 ]
 
 [[package]]
@@ -1720,12 +1719,6 @@ dependencies = [
  "memchr",
 ]
 
-[[package]]
-name = "xdg"
-version = "2.5.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "213b7324336b53d2414b2db8537e56544d981803139155afa84f76eeebb7a546"
-
 [[package]]
 name = "yansi"
 version = "1.0.1"

Cargo.toml

@@ -31,7 +31,6 @@
   tower-http = { version = "0.6.2", features = ["trace"] }
   tracing = "0.1.41"
   tracing-subscriber = { version = "0.3.19", features = ["json", "env-filter"] }
-  xdg = "2.5.2"
 
 [features]
   tokio-console = ["dep:console-subscriber", "tokio/tracing"]

src/iocaine/cli.rs

@@ -15,11 +15,6 @@ pub struct Args {
 
 impl Args {
     fn xdg_config_file() -> String {
-        xdg::BaseDirectories::with_prefix("iocaine")
-            .unwrap()
-            .place_config_file("config.toml")
-            .expect("cannot create configuration directory")
-            .display()
-            .to_string()
+        "config.toml".to_string()
     }
 }