Duplicate entry in `lsp --help`

[jubnzv]

Your environment

Linux, haskell-language-server Version 1.6.1.0, Git revision f4022c5 (dirty) x86_64 ghc-8.10.7.

Steps to reproduce

Run: haskell-language-server lsp -h

Actual behavior

The last line is duplicated in the output of the command:

Usage: haskell-language-server lsp 
  Start talking to an LSP client

Available options:
  -h,--help                Show this help text
  -h,--help                Show this help text

Expected behavior

No duplicate for -h,--help Show this help text.