patch 8.2.0074: Python 3 unicode test someitmes fails

Problem:    Python 3 unicode test someitmes fails.
Solution:   Make 'termencoding' empty.  Correct number of error message.
diff --git a/src/change.c b/src/change.c
index f2dfc93..e5ac97b 100644
--- a/src/change.c
+++ b/src/change.c
@@ -1218,7 +1218,7 @@
     // If "count" is negative the caller must be doing something wrong.
     if (count < 1)
     {
-	siemsg("E950: Invalid count for del_bytes(): %ld", count);
+	siemsg("E292: Invalid count for del_bytes(): %ld", count);
 	return FAIL;
     }