ui-shared: remove cgit_print_date()

There are no longer any users of this function.

Signed-off-by: John Keeping <john@keeping.me.uk>

ui-shared.h

@@ -62,7 +62,6 @@ extern void cgit_print_error(const char *fmt, ...);
 __attribute__((format (printf,1,0)))
 extern void cgit_vprint_error(const char *fmt, va_list ap);
 extern const struct date_mode *cgit_date_mode(const char *format);
-extern void cgit_print_date(time_t secs, const char *format, int local_time);
 extern void cgit_print_age(time_t t, int tz, time_t max_relative);
 extern void cgit_print_http_headers(void);
 extern void cgit_redirect(const char *url, bool permanent);