cli: integer arithmetic safe by default w/o checked (#1758)

cli/src/template.rs

@@ -65,6 +65,9 @@ no-log-ix-name = []
 cpi = ["no-entrypoint"]
 default = []
 
+[profile.release]
+overflow-checks = true
+
 [dependencies]
 anchor-lang = "{2}"
 "#,