[evolution] EWebDAVConfigLookup: Clear output GError before using it

[Milan Crha <mcrha src gnome org>]

commit a2cd6c00819295bfe86fa76257751ae3fbcaef8d
Author: Milan Crha <mcrha redhat com>
Date:   Mon May 25 15:20:07 2020 +0200

    EWebDAVConfigLookup: Clear output GError before using it
    
    To avoid override of it in g_propagate_error(), which produces a runtime
    warning, when there are set multiple servers and the former have failures.

 src/modules/config-lookup/e-webdav-config-lookup.c | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/src/modules/config-lookup/e-webdav-config-lookup.c 
b/src/modules/config-lookup/e-webdav-config-lookup.c
index bb00773a12..e77951dcaf 100644
--- a/src/modules/config-lookup/e-webdav-config-lookup.c
+++ b/src/modules/config-lookup/e-webdav-config-lookup.c
@@ -380,6 +380,8 @@ webdav_config_lookup_worker_run (EConfigLookupWorker *lookup_worker,
                                url = g_strconcat ("https://";, servers_strv[ii], NULL);
                        }
 
+                       g_clear_error (error);
+
                        should_stop = webdav_config_lookup_discover (dummy_source, url, trust_response, 
certificate, config_lookup,
                                params, out_restart_params, &authentication_failed, cancellable, error);