Wrong usage of "keywords" changes document font size about lni

[sieversMartin]

Please note, that there is no macro \keywords, but only an environment keywords. The same mistake is often made within the standard classes using \abstract which does not exist as a macro as well.

It does only work, because defining an environment env in LaTeX ends with two macros \env and \endenv internally.

So, by using \keywords you get the layout changes, but due to the missing \endkeywords the font setup is not reset. The same happens with the space in #13.

I might however add a check to inform the author about it.

[sieversMartin]

I added a check.