remove two unused keys

www/common/translations/messages.json

@@ -51,7 +51,6 @@
     "initializing": "Initializing...",
     "forgotten": "Moved to the trash",
     "errorState": "Critical error: {0}",
-    "lag": "Lag",
     "readonly": "Read only",
     "anonymous": "Anonymous",
     "users": "Users",
@@ -508,7 +507,6 @@
     "mdToolbar_check": "Task list",
     "mdToolbar_code": "Code",
     "mdToolbar_toc": "Table of Contents",
-    "home_product": "CryptPad is a private-by-design alternative to popular office tools and cloud services. All the content stored on CryptPad is encrypted before being sent, which means nobody can access your data unless you give them the keys (not even us).",
     "home_host": "This is an independent community instance of CryptPad.",
     "main_catch_phrase": "Collaboration suite,<br>encrypted and open-source",
     "footer_aboutUs": "About us",