bpo-17535: Increase line number horizontal padding by 2 pixels (GH-14959)

(cherry picked from commit 46ebd4a6a22431ce9676546d2bbe5a6dcd1cc1c1)

Co-authored-by: Tal Einat <taleinat@gmail.com>
diff --git a/Lib/idlelib/sidebar.py b/Lib/idlelib/sidebar.py
index 8f9bf80..76964a4 100644
--- a/Lib/idlelib/sidebar.py
+++ b/Lib/idlelib/sidebar.py
@@ -51,7 +51,7 @@
 
         _padx, pady = get_widget_padding(self.text)
         self.sidebar_text = tk.Text(self.parent, width=1, wrap=tk.NONE,
-                                    padx=0, pady=pady,
+                                    padx=2, pady=pady,
                                     borderwidth=0, highlightthickness=0)
         self.sidebar_text.config(state=tk.DISABLED)
         self.text['yscrollcommand'] = self.redirect_yscroll_event