chore: remove all compiler and clippy warnings

gpodder_sqlite/src/models/device.rs

@@ -17,10 +17,8 @@ use crate::schema::*;
 pub struct Device {
     pub id: i64,
     pub device_id: String,
-    pub user_id: i64,
     pub caption: String,
     pub type_: DeviceType,
-    pub sync_group_id: Option<i64>,
 }
 
 #[derive(Insertable)]

gpodder_sqlite/src/models/device_subscription.rs

@@ -6,8 +6,6 @@ use crate::schema::*;
 #[diesel(table_name = device_subscriptions)]
 #[diesel(check_for_backend(diesel::sqlite::Sqlite))]
 pub struct DeviceSubscription {
-    pub id: i64,
-    pub device_id: i64,
     pub podcast_url: String,
     pub time_changed: i64,
     pub deleted: bool,

gpodder_sqlite/src/models/episode_action.rs

@@ -16,9 +16,6 @@ use crate::schema::*;
 #[diesel(table_name = episode_actions)]
 #[diesel(check_for_backend(diesel::sqlite::Sqlite))]
 pub struct EpisodeAction {
-    pub id: i64,
-    pub user_id: i64,
-    pub device_id: Option<i64>,
     pub podcast_url: String,
     pub episode_url: String,
     pub time_changed: i64,