fix(gui): don't use hardcoded color for link component (#1398)

jadx-gui/src/main/java/jadx/gui/utils/Link.java

 package jadx.gui.utils;
 
-import java.awt.Color;
 import java.awt.Cursor;
 import java.awt.Desktop;
+import java.awt.event.MouseAdapter;
 import java.awt.event.MouseEvent;
-import java.awt.event.MouseListener;
 import java.util.Map;
 
 import javax.swing.JLabel;
@@ -16,7 +15,7 @@ import org.slf4j.LoggerFactory;
 
 import static java.awt.Desktop.Action;
 
-public class Link extends JLabel implements MouseListener {
+public class Link extends JLabel {
 	private static final long serialVersionUID = 3655322136444908178L;
 
 	private static final Logger LOG = LoggerFactory.getLogger(Link.class);
@@ -26,34 +25,15 @@ public class Link extends JLabel implements MouseListener {
 	public Link(String text, String url) {
 		super(text);
 		this.url = url;
-		this.setToolTipText("Open " + url + " in your browser");
-		this.addMouseListener(this);
-		this.setForeground(Color.BLUE);
-	}
-
-	@Override
-	public void mouseClicked(MouseEvent arg0) {
-		browse();
-	}
-
-	@Override
-	public void mouseEntered(MouseEvent arg0) {
-		setCursor(new Cursor(Cursor.HAND_CURSOR));
-	}
-
-	@Override
-	public void mouseExited(MouseEvent arg0) {
-		setCursor(new Cursor(Cursor.DEFAULT_CURSOR));
-	}
-
-	@Override
-	public void mousePressed(MouseEvent arg0) {
-		// ignore
-	}
-
-	@Override
-	public void mouseReleased(MouseEvent arg0) {
-		// ignore
+		setText(text);
+		setToolTipText("Open " + url + " in your browser");
+		setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));
+		this.addMouseListener(new MouseAdapter() {
+			@Override
+			public void mouseClicked(MouseEvent e) {
+				browse();
+			}
+		});
 	}
 
 	private void browse() {
@@ -69,14 +49,13 @@ public class Link extends JLabel implements MouseListener {
 			}
 		}
 		try {
-			String os = System.getProperty("os.name").toLowerCase();
-			if (os.contains("win")) {
+			if (SystemInfo.IS_WINDOWS) {
 				new ProcessBuilder()
 						.command(new String[] { "rundll32", "url.dll,FileProtocolHandler", url })
 						.start();
 				return;
 			}
-			if (os.contains("mac")) {
+			if (SystemInfo.IS_MAC) {
 				new ProcessBuilder()
 						.command(new String[] { "open", url })
 						.start();