fix: remove warnings

src/client_server/account.rs

src/client_server/context.rs

src/client_server/membership.rs

src/client_server/push.rs

src/client_server/state.rs

src/client_server/sync.rs

src/client_server/tag.rs

src/client_server/to_device.rs

src/database/abstraction/sqlite.rs

src/database/pusher.rs

src/database/rooms.rs

src/database/sending.rs

src/server_server.rs