Add try/except to prevent error if the lambda return None

[microhobby]

This is useful to create conditional sections that may return None:

$PL_EXTRA_SEC = {
    "user": lambda: [
                    f"   {username} ",
                    "WHITE",
                    "#00106d"
                ],
    "git_hash": lambda: [
                    f" {_git_hash()} ",
                    "BLACK",
                    "#cf8e00"
                ] if _git_hash() else None
}