Address results of PVS-Studio static analysis

Couple are left un-addressed, see #958 for details.

include/internal/catch_impl.hpp

@@ -58,7 +58,6 @@ namespace Catch {
     IRunner::~IRunner() {}
     IMutableContext::~IMutableContext() {}
     IConfig::~IConfig() {}
-    Matchers::Impl::MatcherUntypedBase::~MatcherUntypedBase() {}
 
     void Config::dummy() {}
 }