Refactor SettingsLoader

Set variable private because it is possible...

src/main/kotlin/SettingsLoader.kt

@@ -54,7 +54,7 @@ class SettingsLoader {
     val appSettings = Properties()
     val sftpSettings = Properties()
     val kafkaProducerProperties = Properties()
-    val mappedYaml: Map<String, Any>
+    private val mappedYaml: Map<String, Any>
 
     init {
         try {