REPORT-30352 直接将RTextAreaBase的border的值改为0，以和8.0版本外观保持一致

designer-base/src/main/java/com/fr/design/gui/syntax/ui/rtextarea/RTextAreaBase.java

@@ -22,9 +22,11 @@ import java.awt.event.MouseEvent;
 import java.awt.event.MouseListener;
 import java.awt.event.MouseMotionListener;
 import javax.swing.JTextArea;
+import javax.swing.border.EmptyBorder;
 import javax.swing.event.CaretEvent;
 import javax.swing.plaf.ColorUIResource;
 import javax.swing.plaf.TextUI;
+import javax.swing.plaf.basic.BasicBorders;
 import javax.swing.text.AbstractDocument;
 import javax.swing.text.BadLocationException;
 import javax.swing.text.Caret;
@@ -645,7 +647,7 @@ int currentCaretY;							// Used to know when to rehighlight current line.
 		setTabsEmulated(false);
 
 		// Stuff needed by the caret listener below.
-		setMargin(getInsets());
+		setBorder(new BasicBorders.MarginBorder());
 		previousCaretY = currentCaretY = getInsets().top;
 
 		// Stuff to highlight the current line.