collect: skip if cache dir doesn't exist

Related to #872

Signed-off-by: Ruslan Kuprieiev <[email protected]>

dvc/remote/local.py

@@ -321,6 +321,7 @@ class RemoteLOCAL(RemoteBase):
                 continue
             if not os.path.exists(cache):
                 missing.append(info)
+                continue
             collected.extend(self.load_dir_cache(md5))
         collected.extend(checksum_infos)
         return collected, missing