patch 8.2.2767: compiler warning for unused argument

Problem:    Compiler warning for unused argument.
Solution:   Remove the argument.
diff --git a/src/blob.c b/src/blob.c
index f020966..114dacd 100644
--- a/src/blob.c
+++ b/src/blob.c
@@ -340,7 +340,7 @@
  * Check if "n1"- is a valid index for a blobl with length "bloblen".
  */
     int
-check_blob_index(long bloblen, varnumber_T n1, int is_range, int quiet)
+check_blob_index(long bloblen, varnumber_T n1, int quiet)
 {
     if (n1 < 0 || n1 > bloblen)
     {