patch 9.1.1391: Vim does not have a vertical tabpanel

Problem:  Vim does not have a tabpanel
Solution: include the tabpanel feature
          (Naruhiko Nishino, thinca)

closes: #17263

Co-authored-by: thinca <thinca@gmail.com>
Signed-off-by: Naruhiko Nishino <naru123456789@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/errors.h b/src/errors.h
index d718507..eddfc1b 100644
--- a/src/errors.h
+++ b/src/errors.h
@@ -3730,3 +3730,5 @@
 #endif
 EXTERN char e_cannot_switch_to_a_closing_buffer[]
 	INIT(= N_("E1546: Cannot switch to a closing buffer"));
+EXTERN char e_cannot_not_support_redrawtabpanel[]
+	INIT(= N_("E1547: This version of Vim does support :redrawtabpanel"));