scripting: JDK 1.5 compatibility: don't use java.awt.Font.MONOSPACED

MONOSPACED is defined in java/awt/Font.java as
/* @since 1.6 */ static final String  MONOSPACED = "Monospaced";

Change-Id: I31847c939387c139971ff55f786773c7ce51448c
Reviewed-on: https://gerrit.libreoffice.org/23164Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: jan iversen <jani@documentfoundation.org>

scripting/java/com/sun/star/script/framework/provider/beanshell/PlainSourceView.java

@@ -137,7 +137,7 @@ public class PlainSourceView extends JScrollPane implements
         ta.setColumns(40);
         ta.setLineWrap(false);
         ta.insert(model.getText(), 0);
-        ta.setFont(new Font(Font.MONOSPACED, ta.getFont().getStyle(), ta.getFont().getSize()));
+        ta.setFont(new Font("Monospaced", ta.getFont().getStyle(), ta.getFont().getSize()));
         undoManager = new UndoManager();
         undoManager.setLimit(noLimit);
         ta.getDocument().addUndoableEditListener(new UndoableEditListener(){