[shotwell] Fix compilation issue with no authenticators enabled

[Jens Georg <jensgeorg src gnome org>]

commit 97c0e4f8829edb18c061fc7acd8fd30c5c5804f8
Author: Jens Georg <mail jensge org>
Date:   Mon Mar 6 21:52:39 2017 +0100

    Fix compilation issue with no authenticators enabled
    
    Signed-off-by: Jens Georg <mail jensge org>

 .../shotwell-publishing/shotwell-publishing.vala   |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/plugins/shotwell-publishing/shotwell-publishing.vala 
b/plugins/shotwell-publishing/shotwell-publishing.vala
index 1c266bf..dce5954 100644
--- a/plugins/shotwell-publishing/shotwell-publishing.vala
+++ b/plugins/shotwell-publishing/shotwell-publishing.vala
@@ -17,6 +17,11 @@ private class ShotwellPublishingCoreServices : Object, Spit.Module {
         var factory = Publishing.Authenticator.Factory.get_instance();
         var authenicators = factory.get_available_authenticators();
 
+        // Prevent vala complaining when all authenticators from this plugin
+        // are disabled
+        debug("Looking for resources in %s", resource_directory.get_path());
+        debug("Found %d authenicators", authenicators.size);
+
 #if HAVE_FACEBOOK
         if (authenicators.contains("facebook")) {
             pluggables += new FacebookService(resource_directory);