patch 8.2.1699: build failure due to missing error message

Problem:    Build failure due to missing error message.
Solution:   Add error message.

Author: brammool

src/errors.h

@@ -266,4 +266,6 @@ EXTERN char e_cannot_change_dict[]
 	INIT(= N_("E1120: Cannot change dict"));
 EXTERN char e_cannot_change_dict_item[]
 	INIT(= N_("E1121: Cannot change dict item"));
+EXTERN char e_variable_is_locked_str[]
+	INIT(= N_("E1122: Variable is locked: %s"));
 #endif

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1699,
 /**/
     1698,
 /**/