fix(current_user): revert set_user_by_token false return when token n…

…ot present (#1306)

app/controllers/devise_token_auth/concerns/set_user_by_token.rb

@@ -62,7 +62,7 @@ def set_user_by_token(mapping = nil)
     # ensure we clear the client
     unless @token.present?
       @token.client = nil
-      return false
+      return
     end
 
     # mitigate timing attacks by finding by uid instead of auth token