Simplify tibble creation in fetchNext

Fixes type collisions with dplyr 1.0.

Change-Id: I89e88437ace022298797f1b81ff99b64bc4fefc5
diff --git a/R/KorAPQuery.R b/R/KorAPQuery.R
index 64ee8c6..3ce4773 100644
--- a/R/KorAPQuery.R
+++ b/R/KorAPQuery.R
@@ -230,7 +230,6 @@
 #'
 #' @aliases fetchNext
 #' @rdname KorAPQuery-class
-#' @importFrom purrr map_dfr
 #' @importFrom dplyr rowwise bind_rows select summarise n
 #' @export
 setMethod("fetchNext", "KorAPQuery", function(kqo, offset = kqo@nextStartIndex, maxFetch = maxResultsPerPage, verbose = kqo@korapConnection@verbose) {
@@ -252,9 +251,7 @@
       }
     }
     currentMatches <-
-      kqo@fields %>%
-      map_dfr( ~tibble(!!.x := logical() ) ) %>%
-      bind_rows(res$matches) %>%
+      res$matches %>%
       dplyr::select(kqo@fields)
     if ("pubDate" %in% kqo@fields) {
       currentMatches$pubDate <-  currentMatches$pubDate %>% as.Date(format = "%Y-%m-%d")