[gnome-clocks] Fix compilation warnins by adding AC_PROG_CC_STDC macro

[Evgeny Bobkin <ebobkin src gnome org>]

commit 5f39c2fdb82045b705b0f4c6f5de871c46517114
Author: Evgeny Bobkin <evgen ibqn gmail com>
Date:   Mon Aug 12 14:47:11 2013 +0200

    Fix compilation warnins by adding AC_PROG_CC_STDC macro
    
    The LTR mark is added to correct the time strings in RTL languges.
    Moreover the AC_PROG_CC_STDC macro was added to configure.ac to
    check for the existence of the ISO Standard C support. This allows the
    usage of unicode character without the compiler warnings. Like in the case
    of LTR mark "\u200E".

 configure.ac |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 8e10dbe..dfd3291 100644
--- a/configure.ac
+++ b/configure.ac
@@ -24,6 +24,7 @@ AC_SUBST([GETTEXT_PACKAGE])
 AC_DEFINE_UNQUOTED(GETTEXT_PACKAGE,"$GETTEXT_PACKAGE",[The name of the gettext domain])
 
 AC_PROG_CC
+AC_PROG_CC_STDC
 AC_PROG_INSTALL
 AC_PROG_MAKE_SET
 AM_PROG_VALAC([0.20.1.19])