Fix compiler warnings associated with AnyMap

include/cantera/base/AnyMap.h

@@ -244,7 +244,7 @@ inline AnyMap& AnyValue::as<AnyMap>() {
         // This is where nested AnyMaps are created when the syntax
         // m[key1][key2] is used.
         if (m_value.type() == typeid(void)) {
-            m_value = std::move(AnyMap());
+            m_value = AnyMap();
         }
         return boost::any_cast<AnyMap&>(m_value);
     } catch (boost::bad_any_cast&) {

src/base/AnyMap.cpp

@@ -73,7 +73,7 @@ AnyValue& AnyMap::operator[](const std::string& key)
         if (iter == m_data.end()) {
             // Create a new key
             AnyValue& value = m_data.insert({head, AnyValue()}).first->second;
-            value = std::move(AnyMap());
+            value = AnyMap();
             value.setKey(head);
             return value.as<AnyMap>()[tail];
         } else {