[Book][Security] remove duplicate label

[xabbuh]

Q	A
Doc fix?	yes
New docs?	no
Applies to	2.5
Fixed tickets

This has been previously fixed in #3456 but somehow slipped through in 8bd668e.

[cordoval]

I wonder why things slip in that way, maybe because of the order of commits or lack of rebase, lack of ripple merging of PRs to older bases? or merges across branches?

[xabbuh]

Yeah, as you can see in the commit mentioned in the PR description, there have been conflicts. Thus, I guess this slipped through when the conflicts were resolved.

For things like this which fix build errors, having the Travis integration running would ease Ryan's work.

[cordoval]

yes i agree. I was wondering if there could be a messup detector as well, like identifying the duplicate lines for instance. he I am always now thinking where can Gush commands help.

[weaverryan]

The line is gone now in master, I think it was simply a lack of me merging the branches up on a timely basis :). But nothing weird is going on.

@xabbuh but yes, I'm excited for the Travis integration - I'm going to find time soon to get that merged in - it will be really great!