Remove obsolete doc link

[rosier]

The link points to a doc page that doesn't exist anymore

[94noni]

did you have a tool for that? asking because it could be relevant to run such process on symfony doc repo to spot failures (if not already the case )

[rosier]

No, I stumbled onto this going thru the code and remembered that the command to generate entity classes based on an existing database was dropped years ago

[javiereguiluz]

Good catch, thanks Jan.