wallet: Avoid showing GUI popups on RPC errors

test/functional/wallet_multiwallet.py

@@ -339,14 +339,10 @@ class MultiWalletTest(BitcoinTestFramework):
         self.log.info("Fail -upgradewallet that results in downgrade")
         assert_raises_rpc_error(
             -4,
-            "Wallet loading failed.",
+            'Wallet loading failed: Error loading {}: Wallet requires newer version of {}'.format(
+                wallet_dir('high_minversion', 'wallet.dat'), self.config['environment']['PACKAGE_NAME']),
             lambda: self.nodes[0].loadwallet(filename='high_minversion'),
         )
-        self.stop_node(
-            i=0,
-            expected_stderr='Error: Error loading {}: Wallet requires newer version of Bitcoin Core'.format(
-                wallet_dir('high_minversion', 'wallet.dat')),
-        )
 
 
 if __name__ == '__main__':