fix lua autocomplete crash when a table contains number keys

src/LuaAPI.cpp

@@ -298,6 +298,7 @@ void LuaAPI::MP::PrintRaw(sol::variadic_args Args) {
 }
 
 int LuaAPI::PanicHandler(lua_State* State) {
+    //FIXME: unsafe operation, can cause stack overflow
     beammp_lua_error("PANIC: " + sol::stack::get<std::string>(State, 1));
     return 0;
 }

src/TLuaEngine.cpp

@@ -253,11 +253,15 @@ std::vector<std::string> TLuaEngine::StateThreadData::GetStateTableKeys(const st
         } else if (i == keys.size() - 1) {
             if (obj.get_type() == sol::type::table) {
                 for (const auto& [key, value] : obj.as<sol::table>()) {
-                    std::string s = key.as<std::string>();
+                    if (key.get_type() == sol::type::string) {
-                    if (value.get_type() == sol::type::function) {
+                        std::string s = key.as<std::string>();
-                        s += "(";
+
+                        if (value.get_type() == sol::type::function) {
+                            s += "(";
+                        }
+
+                        Result.push_back(s);
                     }
-                    Result.push_back(s);
                 }
             } else {
                 Result = { obj.as<std::string>() };