Make previous changes backwards-compatible

Depending on the existence of the original config location, uses it or
the new location

This prevents the backwards-incompatible change at the cost of some
checking on every config query.

spotify_player/src/config/mod.rs

@@ -1,6 +1,7 @@
 mod keymap;
 mod theme;
 
+const DEFAULT_CONFIG_FOLDER: &str = ".config/spotify-player";
 const APP_CONFIG_FILE: &str = "app.toml";
 const THEME_CONFIG_FILE: &str = "theme.toml";
 const KEYMAP_CONFIG_FILE: &str = "keymap.toml";
@@ -323,10 +324,17 @@ const APP_NAME: &str = "spotify-player";
 
 /// gets the application's configuration folder path
 pub fn get_config_folder_path() -> Result<PathBuf> {
-    match dirs_next::config_dir() {
-        Some(config_home) => Ok(config_home.join(APP_NAME)),
-        None => Err(anyhow!("cannot find the $HOME folder")),
+    if let Some(home) = dirs_next::home_dir() {
+        let old_path = home.join(DEFAULT_CONFIG_FOLDER);
+        if old_path.exists() {
+            return Ok(old_path);
+        }
     }
+    if let Some(config_home) = dirs_next::config_dir() {
+        return Ok(config_home.join(APP_NAME));
+    }
+
+    Err(anyhow!("cannot find the $HOME folder"))
 }
 
 /// gets the application's cache folder path