[sysprof] app: add missing locale.h include

[Christian Hergert <chergert src gnome org>]

commit 9abac0931e226686502843640f2b8cbd1c4d05a7
Author: Christian Hergert <chergert redhat com>
Date:   Sat Sep 29 14:09:13 2018 -0700

    app: add missing locale.h include

 src/sp-application.c | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/src/sp-application.c b/src/sp-application.c
index a289239..280960c 100644
--- a/src/sp-application.c
+++ b/src/sp-application.c
@@ -19,6 +19,7 @@
 #include "config.h"
 
 #include <glib/gi18n.h>
+#include <locale.h>
 
 #include "sp-application.h"
 #include "sp-credits.h"