Fixes leave on the server and reworked login flow.

gamenight-database/src/error.rs

@@ -1,3 +1,4 @@
+#[derive(Debug)]
 pub struct DatabaseError(pub String);
 
 impl From<diesel::result::Error> for DatabaseError {

gamenight-database/src/gamenight_participants.rs

@@ -28,7 +28,9 @@ pub fn insert_gamenight_participant(conn: &mut DbConnection, gp: GamenightPartic
 }
 
 pub fn delete_gamenight_participant(conn: &mut DbConnection, gp: GamenightParticipant) -> Result<usize, DatabaseError> {
-    Ok(gamenight_participant::table
-        .filter(gamenight_participant::gamenight_id.eq(&gp.gamenight_id).and(gamenight_participant::user_id.eq(gp.user_id)))
+    Ok(diesel::delete(gamenight_participant::table
+        .filter(gamenight_participant::gamenight_id.eq(&gp.gamenight_id)
+            .and(gamenight_participant::user_id.eq(gp.user_id))))
         .execute(conn)?)
+
 }