[librest] tests: Don't call soup_message_headers_get with newer libsoup

[Christophe Fergeau <teuf src gnome org>]

commit ec8fffcc36f10be6f9df71694cc91796463a6219
Author: Christophe Fergeau <cfergeau redhat com>
Date:   Tue Sep 2 14:00:09 2014 +0200

    tests: Don't call soup_message_headers_get with newer libsoup
    
    This is deprecated and causes compile-time warnings
    
    https://bugzilla.gnome.org/show_bug.cgi?id=735921

 tests/proxy.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/tests/proxy.c b/tests/proxy.c
index 36414de..74379e8 100644
--- a/tests/proxy.c
+++ b/tests/proxy.c
@@ -36,6 +36,11 @@
 #include <libsoup/soup.h>
 #include <rest/rest-proxy.h>
 
+#if SOUP_CHECK_VERSION (2, 28, 0)
+/* Avoid deprecation warning with newer libsoup */
+#define soup_message_headers_get soup_message_headers_get_one
+#endif
+
 static int errors = 0;
 
 static void