on a sync conflict with a local empty deck, force download

aqt/sync.py

@@ -289,6 +289,10 @@ class SyncThread(QThread):
         self._syncMedia()
 
     def _fullSync(self):
+        # if the local deck is empty, assume user is trying to download
+        if self.col.isEmpty():
+            f = "download"
+        else:
             # tell the calling thread we need a decision on sync direction, and
             # wait for a reply
             self.fullSyncChoice = False