avoid rescaled fonts, e.g. dockable buttons on Windows L&F after opening a new view;

--- a/src/Tools/jEdit/src-base/plugin.scala	Fri Jan 08 19:52:10 2021 +0100
+++ b/src/Tools/jEdit/src-base/plugin.scala	Fri Jan 08 22:30:32 2021 +0100
@@ -19,6 +19,8 @@
   {
     Isabelle_System.init()
 
+    GUI.use_isabelle_fonts()
+
     Debug.DISABLE_SEARCH_DIALOG_POOL = true
 
     Syntax_Style.dummy_style_extender()

--- a/src/Tools/jEdit/src/plugin.scala	Fri Jan 08 19:52:10 2021 +0100
+++ b/src/Tools/jEdit/src/plugin.scala	Fri Jan 08 22:30:32 2021 +0100
@@ -401,8 +401,6 @@
             if (buffer != null && text_area != null) init_view(buffer, text_area)
           }
 
-          GUI.use_isabelle_fonts()
-
           spell_checker.update(options.value)
           session.update_options(options.value)