patch 9.1.0035: i_CTRL-] triggers InsertCharPre

Problem:  i_CTRL-] triggers InsertCharPre
Solution: Return if CTRL-] is received. InsertCharPre
          is supposed to be only used for chars to be inserted
          but i_CTRL-] triggers expansion and is not inserted
          into the buffer (altermo)

closes: #13853
closes: #13864

Signed-off-by: altermo
Signed-off-by: Christian Brabandt <cb@256bit.org>

src/edit.c

@@ -5371,6 +5371,9 @@ do_insert_char_pre(int c)
     if (!has_insertcharpre())
 	return NULL;
 
+    if (c == Ctrl_RSB)
+	return NULL;
+
     if (has_mbyte)
 	buf[(*mb_char2bytes)(c, buf)] = NUL;
     else