[gnome-control-center] tz.c: compiler warning: implicit declaration of function ‘islower’

[Rui Matos <rtcm src gnome org>]

commit f090d7e3a0018ac5d8af1d42e6af507f4a70c6ac
Author: Alan Coopersmith <alan coopersmith oracle com>
Date:   Sat Jun 10 12:28:34 2017 -0700

    tz.c: compiler warning: implicit declaration of function ‘islower’
    
    https://bugzilla.gnome.org/show_bug.cgi?id=783641
    
    Signed-off-by: Alan Coopersmith <alan coopersmith oracle com>

 panels/datetime/tz.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/panels/datetime/tz.c b/panels/datetime/tz.c
index 0eac576..d711867 100644
--- a/panels/datetime/tz.c
+++ b/panels/datetime/tz.c
@@ -29,6 +29,7 @@
 #include <time.h>
 #include <math.h>
 #include <string.h>
+#include <ctype.h>
 #include "tz.h"
 #include "cc-datetime-resources.h"