NWN: Don't implicitly depend on explicit ScopedPtr bool conversion

Because this won't compile in C++11 mode, by design.

src/engines/nwn/gui/ingame/ingame.cpp

@@ -172,7 +172,7 @@ void IngameGUI::updatePartyMember(size_t partyMember, const Creature &creature,
 }
 
 bool IngameGUI::hasRunningConversation() const {
-	return _dialog != 0;
+	return _dialog.get() != 0;
 }
 
 bool IngameGUI::startConversation(const Common::UString &conv,