Fix merge compilation error

Avoid GUI code in the processing code because that make the CLI fails
otherwise.

Author: tbouffard

src/main/java/com/mxgraph/svg2xml/Svg2Xml.java

@@ -25,7 +25,7 @@
 import java.util.List;
 import java.util.Map;
 
-import javax.swing.JOptionPane;
+//import javax.swing.JOptionPane;
 import javax.xml.parsers.DocumentBuilder;
 import javax.xml.parsers.DocumentBuilderFactory;
 import javax.xml.transform.OutputKeys;
@@ -662,7 +662,9 @@ else if (aspectRatio.toLowerCase().equals("variable"))
 			}
 		}
 
-		JOptionPane.showMessageDialog(gui.getFrame(), "Conversion completed.\nThe libraries are genereted in:" + destFolders);
+		// TODO: if we need to have a dialog message in the GUI, we should
+		// provide a PR in the upstream repository to ensure there is no GUI code here (this prevents usage of the tool with the CLI)
+		// JOptionPane.showMessageDialog(gui.getFrame(), "Conversion completed.\nThe libraries are genereted in:" + destFolders);
 	}
 
 	/**