enable auto check for update programmatically;
using plist somehow caused dock icon to appear;

Change-Id: I97f34d6d5b5697cf2e2cd42ddc9cb7d3190bbbdf
diff --git a/osx/auto-update/sparkle-auto-update.mm b/osx/auto-update/sparkle-auto-update.mm
index ef59657..1474775 100644
--- a/osx/auto-update/sparkle-auto-update.mm
+++ b/osx/auto-update/sparkle-auto-update.mm
@@ -36,6 +36,8 @@
   d->updater = [[SUUpdater sharedUpdater] retain];
   NSURL *url = [NSURL URLWithString: [NSString stringWithUTF8String: updateUrl.toUtf8().data()]];
   [d->updater setFeedURL: url];
+  [d->updater setAutomaticallyChecksForUpdates: YES];
+  [d->updater setUpdateCheckInterval: 86400];
 }
 
 SparkleAutoUpdate::~SparkleAutoUpdate()