fix(gpodder_sqlite): force in-memory database to consist of only one connection

gpodder_sqlite/src/lib.rs

@@ -98,6 +98,10 @@ pub fn initialize_db(path: impl AsRef<Path>, run_migrations: bool) -> Result<DbP
 pub fn initialize_db_in_memory(run_migrations: bool) -> Result<DbPool, DbError> {
     let manager = ConnectionManager::<SqliteConnection>::new(":memory:");
     let pool = Pool::builder()
+        // An in-memory database is recreated for each opened connection, so we try to force only a
+        // single connection to stay alive
+        .min_idle(Some(1))
+        .max_size(1)
         .connection_customizer(Box::new(AddQueryDebugLogs))
         .build(manager)?;