patch 8.2.1976: cannot backspace in prompt buffer after using cursor-left

Problem:    Cannot backspace in prompt buffer after using cursor-left. (Maxim
            Kim)
Solution:   Ignore "arrow_used" in a prompt buffer. (closes #7281)
diff --git a/src/version.c b/src/version.c
index 872c25a..28f95cf 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1976,
+/**/
     1975,
 /**/
     1974,