Removing option with a link causes an error

[OlivierHartmann]

Hello,

Thank you for this work.
I have found an issue while removing an option that has a link with another one.
Here is a minimalist example causing the bug:

#include <CLI/CLI.hpp>

int main(int argc, char **argv) {

    CLI::App app{"App to demonstrate a bug."};

    int foo, bar;
    auto foo_option = app.add_option("--foo,-f", foo, "An argument");
    app.add_option("--bar", bar, "Another argument")->excludes(foo_option);

    app.remove_option(foo_option);

    CLI11_PARSE(app, argc, argv);
}

Then when running with the "help" flag, we get the following error:

   terminate called after throwing an instance of 'std::bad_alloc'
     what():  std::bad_alloc
   Abandon (core dumped)

The solution can therefore simply be to delete the links at the same time as deleting the option.

Thank you

Olivier

[henryiii]

This just needs to be checked as part of remove_option, should be pretty easy to add.