Fix for libical >= 4

Index: src/calendar_notes.h
--- src/calendar_notes.h.orig
+++ src/calendar_notes.h
@@ -53,7 +53,7 @@ enum {     
 
 gboolean    cal_check_note              (guint32 julian, GUI *appGUI);
 gboolean    cal_check_notes             (guint32 julian_start, guint32 julian_end, GUI *appGUI);
-void        cal_notes_foreach           (guint32 julian_start, guint32 julian_end, gboolean (*cnfunc)(), GUI *appGUI);
+void        cal_notes_foreach           (guint32 julian_start, guint32 julian_end, gboolean (*cnfunc)(struct note*, GUI*), GUI *appGUI);
 gchar *     cal_get_note                (guint32 julian, GUI *appGUI);
 gchar *     cal_get_note_color          (guint32 julian, GUI *appGUI);
 void        cal_replace_note_color      (gchar *old_color, gchar *new_color, GUI *appGUI);
