Updated log4j to 2.17.1

This involves modifying the log4j2.properties file on node startup to fix an incompatibility with ${dirname:-}. Thanks to AlphaX Projects for tracking down this incompatibility.

src/main/java/org/qortal/controller/Controller.java

@@ -366,6 +366,8 @@ public class Controller extends Thread {
 	// Entry point
 
 	public static void main(String[] args) {
+		LoggingUtils.fixLegacyLog4j2Properties();
+
 		LOGGER.info("Starting up...");
 
 		// Potential GUI startup with splash screen, etc.

src/main/java/org/qortal/utils/LoggingUtils.java

@@ -0,0 +1,31 @@
+package org.qortal.utils;
+
+import org.apache.commons.io.FileUtils;
+import org.apache.logging.log4j.LogManager;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
+public class LoggingUtils {
+
+    public static void fixLegacyLog4j2Properties() {
+        Path log4j2PropertiesPath = Paths.get("log4j2.properties");
+        if (Files.exists(log4j2PropertiesPath)) {
+            try {
+                String content = FileUtils.readFileToString(log4j2PropertiesPath.toFile(), "UTF-8");
+                if (content.contains("${dirname:-}")) {
+                    content = content.replace("${dirname:-}", "./");
+                    FileUtils.writeStringToFile(log4j2PropertiesPath.toFile(), content, "UTF-8");
+
+                    // Force reload the log4j2.properties file
+                    ((org.apache.logging.log4j.core.LoggerContext) LogManager.getContext(false)).reconfigure();
+                }
+            } catch (IOException e) {
+                // Not much we can do here
+            }
+        }
+    }
+
+}