patch 9.1.0147: Cannot keep a buffer focused in a window

Problem:  Cannot keep a buffer focused in a window
          (Amit Levy)
Solution: Add the 'winfixbuf' window-local option
          (Colin Kennedy)

fixes:  #6445
closes: #13903

Signed-off-by: Colin Kennedy <colinvfx@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/errors.h b/src/errors.h
index dd2bc95..65ee4e8 100644
--- a/src/errors.h
+++ b/src/errors.h
@@ -3607,3 +3607,5 @@
 	INIT(= N_("E1511: Wrong number of characters for field \"%s\""));
 EXTERN char e_wrong_character_width_for_field_str[]
 	INIT(= N_("E1512: Wrong character width for field \"%s\""));
+EXTERN char e_winfixbuf_cannot_go_to_buffer[]
+	INIT(= N_("E1513: Cannot edit buffer. 'winfixbuf' is enabled"));