Only build virDomainObjFormat if not building proxy.

While building under RHEL-5, I got a compile warning because
virDomainObjFormat was defined but not used.  That came about
because in RHEL-5 we build with "#define PROXY", and
virDomainObjFormat is only used with !PROXY.  Move the
define.
Signed-off-by: NChris Lalancette <clalance@redhat.com>

src/conf/domain_conf.c

@@ -5660,6 +5660,8 @@ char *virDomainDefFormat(virDomainDefPtr def,
     return NULL;
 }
 
+#ifndef PROXY
+
 static char *virDomainObjFormat(virCapsPtr caps,
                                 virDomainObjPtr obj,
                                 int flags)
@@ -5695,9 +5697,6 @@ error:
     return NULL;
 }
 
-
-#ifndef PROXY
-
 int virDomainSaveXML(const char *configDir,
                      virDomainDefPtr def,
                      const char *xml)