Use legacy tripcode algorithm by default

It's more secure.

config.toml

@@ -62,7 +62,7 @@ max_name_length = 24
 min_name_contrast = 3.0
 background_color = "#232327"
 max_tripcode_password_length = 1024
-legacy_tripcode_algorithm = false
+legacy_tripcode_algorithm = true
 force_captcha_every = 40
 
 [flood.messages]