fixed error when visiting root of object

source/RobotAPI/libraries/armem/server/RemoteGuiAronDataVisitor.h

@@ -38,7 +38,7 @@ namespace armarx::armem::server
         void visitDictOnEnter(const aron::data::VariantPtr& n) override
         {
             ARMARX_CHECK_NOT_NULL(n);
-            const std::string key = n->getPath().getLastElement();
+            const std::string key = n->getPath().size() > 0 ? n->getPath().getLastElement() : ""; // check if root of object
             visitEnter(key, "dict", n->childrenSize());
         }
         void visitDictOnExit(const aron::data::VariantPtr&) override