Update security.rst

[mpaquet]

Q	A
Doc fix?	yes
New docs?	no
Applies to	<2.7
Fixed tickets	#5698

[wouterj]

Hmm, I'm not sure if I like creating a complete box for this. It's important, but it isn't really important for the article itself.

What about changing the sentence in the article to something like this:

For hardcoded users, you can use an `online tool`_ (do not use it with real passwords),
which will give you something like this:

[mpaquet]

You have a point but the explanation is still relevant imho and should stay.

For hardcoded users, you can use an online tool_ (this is a public tool and it should not be used with real passwords because of the risk of farming or other security issues), which will give you something like this:

[wouterj]

Thank you @mpaquet! I've merged your PR into the docs now.

I've changed the wording a bit in d2c3e26, it's not our task to explain why it's a security risk to use real passwords. It's our task to just warn people to do not it, if they want more information they can easily google it.

Thanks again!