* Fix DialogActionManager::send_dialog_action in secret chats
The code in `DialogActionManager::send_dialog_action` made the assumption that since we'd either have early returned or `DialogManager::have_input_peer` would be true, and therefore the else block of the conditional, which intended to set input_peer, should have done so successfully.
However, `DialogManager::have_input_peer` will return true for secret chats when `contacts_manager->have_input_encrypted_peer`
And `DialogManager::get_input_peer` will return a `nullptr` for secret chats by design (I believe this is because they operate using structures that are currently incompatible)
This should fix the root of a crash that happens when typing in or sending messages to secret chats on:
Telegram X 0.26.4.1678-arm64-v8a (99b10675)
TDLib: 1.8.23 (tdlib/td@4bafdc2)
* Move CHECK below SecretChat case instead per feedback
