Your Twitter account is now more secured. Twitter added a user setting that lets you always use HTTPS secured connection when you are accessing Twitter.com. You can go to https://twitter.com to use Twitter via HTTPS. With this option in settings you no need to type https://twitter.com every time you go to Twitter. Based on your setting it will automatically use HTTPS.
Login to your Twitter account, then go to settings and check the box “Always use HTTPS” which is located just before Save button. Twitter left the decision to you, HTTPS is not default as of now. But using HTTPS is better to secure your account.