sync: Fix long running bug known as "why my fresh uploaded file is now empty again"

Thanks to Nicolas Ribeyrolle

admin/sync/importer_localfs.go

@@ -47,9 +47,11 @@ func (i LocalImporter) importFile(URI string, next func(string, string) (interfa
 		} else {
 			os.Symlink(i.toURL(URI) + "_MERGED", dest)
 		}
-	}
 
-	return ImportFile(i, URI, next)
+		return next(dest, URI)
+	} else {
+		return ImportFile(i, URI, next)
+	}
 }
 
 func (i LocalImporter) getFile(filename string, writer *bufio.Writer) error {