Remove explicit call of destructor

Author: james-d-mitchell

tests/test-konieczny-bmat8-3.cpp

@@ -304,7 +304,6 @@ namespace libsemigroups {
 
     Konieczny<BMat8> KW;
     KW = std::move(KV);
-    KV.~Konieczny();
     REQUIRE(KW.current_number_of_D_classes() == found_classes);
     KW.run();
     LIBSEMIGROUPS_ASSERT(KW.number_of_D_classes() == 66);