Use \exp_last_unbraced:Nf to remove spaces in l3token

After finding out that the next token is a space, it is safe (and
faster) to remove it using f-expansion.  Thanks to Qing Lee.


git-svn-id: http://www.latex-project.org/svnroot/experimental/trunk@4396 de43f980-851b-0410-b2f7-c40aca1f87e0
Typo


git-svn-id: http://www.latex-project.org/svnroot/experimental/trunk@4397 de43f980-851b-0410-b2f7-c40aca1f87e0