Merge bitcoin-core#102: Fix SplashScreen crash when run with -disablewallet

c056064 gui: Fix SplashScreen crash when run with -disablewallet (Hennadii Stepanov)

Pull request description:

  This PR fixes the bug introduced in bitcoin/bitcoin#19099:

  ```
  $ src/qt/bitcoin-qt -disablewallet
  bitcoin-qt: interfaces/node.cpp:236: auto interfaces::(anonymous namespace)::NodeImpl::walletClient()::(anonymous class)::operator()() const: Assertion `"m_context->wallet_client" && check' failed.
  Aborted (core dumped)
  ```

ACKs for top commit:
  Sjors:
    tACK c056064
  promag:
    ACK c056064.

Tree-SHA512: 263d9efd5899cc6e447dfc5142bf911ca627149fac0a1c5e5b58dd196aa5e0d12fe13e3f750fb5f3c4338222f7959935d2f77391263f967dbca2e0e79a416a29

Author: MarcoFalke

src/qt/splashscreen.cpp

@@ -14,6 +14,7 @@
 #include <interfaces/wallet.h>
 #include <qt/guiutil.h>
 #include <qt/networkstyle.h>
+#include <qt/walletmodel.h>
 #include <util/system.h>
 #include <util/translation.h>
 
@@ -196,6 +197,7 @@ void SplashScreen::subscribeToCoreSignals()
 void SplashScreen::handleLoadWallet()
 {
 #ifdef ENABLE_WALLET
+    if (!WalletModel::isWalletEnabled()) return;
     m_handler_load_wallet = m_node->walletClient().handleLoadWallet([this](std::unique_ptr<interfaces::Wallet> wallet) {
         m_connected_wallet_handlers.emplace_back(wallet->handleShowProgress(std::bind(ShowProgress, this, std::placeholders::_1, std::placeholders::_2, false)));
         m_connected_wallets.emplace_back(std::move(wallet));