BUILD/MINOR: fix the source URL in the spec file

As reported by Avi Brender, the soruce URL was still pointing to v1.3.
diff --git a/examples/haproxy.spec b/examples/haproxy.spec
index 865cb77..88021b1 100644
--- a/examples/haproxy.spec
+++ b/examples/haproxy.spec
@@ -5,7 +5,7 @@
 License: GPL
 Group: System Environment/Daemons
 URL: http://haproxy.1wt.eu/
-Source0: http://haproxy.1wt.eu/download/1.3/src/%{name}-%{version}.tar.gz
+Source0: http://haproxy.1wt.eu/download/1.5/src/devel/%{name}-%{version}.tar.gz
 BuildRoot: %{_tmppath}/%{name}-%{version}-root
 BuildRequires: pcre-devel
 Requires: /sbin/chkconfig, /sbin/service