patch 8.1.1124: insert completion flags are mixed up

Problem:    Insert completion flags are mixed up.
Solution:   Clean up flags use of ins_compl_add() and cp_flags.

src/spell.c

@@ -8627,7 +8627,7 @@ dump_word(
 		    ? MB_STRNICMP(p, pat, STRLEN(pat)) == 0
 		    : STRNCMP(p, pat, STRLEN(pat)) == 0)
 		&& ins_compl_add_infercase(p, (int)STRLEN(p),
-					  p_ic, NULL, *dir, 0) == OK)
+					  p_ic, NULL, *dir, FALSE) == OK)
 	/* if dir was BACKWARD then honor it just once */
 	*dir = FORWARD;
 }