gitk: Set the font for all listbox widgets

This affects the font chooser.
Signed-off-by: NMark Hills <mark@pogo.org.uk>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

gitk

@@ -1880,6 +1880,7 @@ proc setoptions {} {
     option add *Entry.font uifont startupFile
     option add *Labelframe.font uifont startupFile
     option add *Spinbox.font textfont startupFile
+    option add *Listbox.font mainfont startupFile
 }
 
 # Make a menu and submenus.