[phodav] spice-webdavd: fix build on Linux

[Marc-Andre Lureau <malureau src gnome org>]

commit c5f8cb47511d3a23acd5f37999ac5579169fb1ff
Author: Marc-André Lureau <marcandre lureau gmail com>
Date:   Tue Feb 10 19:26:41 2015 +0100

    spice-webdavd: fix build on Linux

 spice/spice-webdavd.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/spice/spice-webdavd.c b/spice/spice-webdavd.c
index 944224e..742f9c9 100644
--- a/spice/spice-webdavd.c
+++ b/spice/spice-webdavd.c
@@ -734,6 +734,8 @@ run_service (void)
      clients */
 
 #ifdef WITH_AVAHI
+  GError *error = NULL;
+
   mdns_client = ga_client_new (GA_CLIENT_FLAG_NO_FLAGS);
   g_signal_connect (mdns_client, "state-changed", G_CALLBACK (mdns_state_changed), NULL);
   if (!ga_client_start (mdns_client, &error))