patch 8.2.3284: no error for insert() or remove() changing a locked blob

Problem:    No error for insert() or remove() changing a locked blob.
Solution:   Check a blob is not locked before changing it. (Sean Dewar,
            closes #8696)
diff --git a/src/errors.h b/src/errors.h
index 44b2828..942cf65 100644
--- a/src/errors.h
+++ b/src/errors.h
@@ -366,7 +366,8 @@
 	INIT(= N_("E1096: Returning a value in a function without a return type"));
 EXTERN char e_line_incomplete[]
 	INIT(= N_("E1097: Line incomplete"));
-// E1098 unused
+EXTERN char e_string_list_or_blob_required[]
+	INIT(= N_("E1098: String, List or Blob required"));
 EXTERN char e_unknown_error_while_executing_str[]
 	INIT(= N_("E1099: Unknown error while executing %s"));
 EXTERN char e_cannot_declare_script_variable_in_function[]