Factor out ETA logging

Change-Id: Ic8b1600395018aa79701e29a38c4ec22d598337a
diff --git a/R/KorAPConnection.R b/R/KorAPConnection.R
index f2d65a8..1d567a8 100644
--- a/R/KorAPConnection.R
+++ b/R/KorAPConnection.R
@@ -13,6 +13,7 @@
 #' @import R.cache
 #' @import utils
 #' @import methods
+#' @include logging.R
 #' @slot KorAPUrl        URL of the web user interface of the KorAP server used in the connection.
 #' @slot apiVersion      requested KorAP API version.
 #' @slot indexRevision   indexRevision code as reported from API via `X-Index-Revision` HTTP header.