http: fix cache configuration marshal/unmarshal

Also, enable Redis by default, as stated in changelog.

akvorado.yaml

@@ -102,6 +102,10 @@ inlet:
       - ClassifyInternal()
 
 console:
+  http:
+    cache:
+      type: redis
+      server: redis:6379
   database:
     saved-filters:
       # These are prepopulated filters you can select in a drop-down

common/helpers/mapstructure.go

@@ -144,7 +144,7 @@ func ParametrizedConfigurationUnmarshallerHook[OuterConfiguration any, InnerConf
 		// Alter config with a copy of the concrete type
 		defaultV := innerConfiguration()
 		original := reflect.Indirect(reflect.ValueOf(defaultV))
-		if !configField.IsNil() && configField.Elem().Type().Elem() == reflect.TypeOf(defaultV).Elem() {
+		if !configField.IsNil() && configField.Elem().Type() == reflect.TypeOf(defaultV) {
 			// Use the value we already have instead of default.
 			original = reflect.Indirect(configField.Elem())
 		}

common/http/config.go

@@ -100,6 +100,16 @@ func DefaultConfiguration() Configuration {
 	}
 }
 
+// MarshalYAML undoes ConfigurationUnmarshallerHook().
+func (cc CacheConfiguration) MarshalYAML() (interface{}, error) {
+	return helpers.ParametrizedConfigurationMarshalYAML(cc, cacheConfigurationMap)
+}
+
+// MarshalJSON undoes ConfigurationUnmarshallerHook().
+func (cc CacheConfiguration) MarshalJSON() ([]byte, error) {
+	return helpers.ParametrizedConfigurationMarshalJSON(cc, cacheConfigurationMap)
+}
+
 var cacheConfigurationMap = map[string](func() CacheBackendConfiguration){
 	"memory": DefaultMemoryCacheConfiguration,
 	"redis":  DefaultRedisCacheConfiguration,