patch 9.0.2132: Duplicate Netbeans Error Message

Problem:  Duplicate Netbeans Error Message
Solution: Remove duplicate message

We have 2 error Messages used for the Netbeans interface:

- EXTERN char e_invalid_buffer_identifier_in_close[]
  INIT(= N_("E648: Invalid buffer identifier in close"));
- EXTERN char e_invalid_buffer_identifier_in_close_2[]
  INIT(= N_("E649: Invalid buffer identifier in close"));

Since the error message is exactly the same, get rid of the  second
message.

closes: #13584

Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/errors.h b/src/errors.h
index 4424337..c8eaac7 100644
--- a/src/errors.h
+++ b/src/errors.h
@@ -1658,8 +1658,7 @@
 	INIT(= N_("E647: Invalid buffer identifier in setDot"));
 EXTERN char e_invalid_buffer_identifier_in_close[]
 	INIT(= N_("E648: Invalid buffer identifier in close"));
-EXTERN char e_invalid_buffer_identifier_in_close_2[]
-	INIT(= N_("E649: Invalid buffer identifier in close"));
+// E649 unused
 EXTERN char e_invalid_buffer_identifier_in_defineannotype[]
 	INIT(= N_("E650: Invalid buffer identifier in defineAnnoType"));
 EXTERN char e_invalid_buffer_identifier_in_addanno[]