Merge #18853: wallet: Fix typo in assert that is compile-time true

fa47cf9d95 wallet: Fix typo in assert that is compile-time true (MarcoFalke)

Pull request description:

  Commit 92bcd70808 presumably added a check that a `dest` of type `CNoDestination` implies an empty `scriptChange`.

  However, it accidentally checked for `boost::variant::empty`, which always returns false: https://www.boost.org/doc/libs/1_72_0/doc/html/boost/variant.html#id-1_3_46_5_4_1_1_16_2-bb

ACKs for top commit:
  Sjors:
    utACK fa47cf9d95

Tree-SHA512: 9626b1e2947039853703932a362c2ee204e002d3344856eb93eef0e0f833401336f2dfa80fd43b83c8ec6eac624e6302aee771fb67aec436ba6483be02b8d615

src/test/script_standard_tests.cpp

@@ -13,6 +13,12 @@
 
 BOOST_FIXTURE_TEST_SUITE(script_standard_tests, BasicTestingSetup)
 
+BOOST_AUTO_TEST_CASE(dest_default_is_no_dest)
+{
+    CTxDestination dest;
+    BOOST_CHECK(!IsValidDestination(dest));
+}
+
 BOOST_AUTO_TEST_CASE(script_standard_Solver_success)
 {
     CKey keys[3];