[libsigc++2] SIGC_CXX_HAS_SUN_REVERSE_ITERATOR: Add std:: now that I removed the using std.

[Murray Cumming <murrayc src gnome org>]

commit c4d9b98c65f9fe0d05e7367d876e361484f56d4f
Author: Murray Cumming <murrayc murrayc com>
Date:   Thu Mar 3 18:21:23 2016 +0100

    SIGC_CXX_HAS_SUN_REVERSE_ITERATOR: Add std:: now that I removed the using std.
    
    See https://bugzilla.gnome.org/show_bug.cgi?id=762065#c2

 build/cxx_std.m4 |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/build/cxx_std.m4 b/build/cxx_std.m4
index e902c55..c9f0700 100644
--- a/build/cxx_std.m4
+++ b/build/cxx_std.m4
@@ -13,7 +13,7 @@ AC_DEFUN([SIGC_CXX_HAS_SUN_REVERSE_ITERATOR],
     [[
       #include <iterator>
     ]],[[
-      typedef reverse_iterator<char*,random_access_iterator_tag,char,char&,char*,int> ReverseIter;
+      typedef std::reverse_iterator<char*, std::random_access_iterator_tag, char, char&, char*, int> 
ReverseIter;
     ]])],
       [sigc_cv_cxx_has_sun_reverse_iterator='yes'],
       [sigc_cv_cxx_has_sun_reverse_iterator='no']