fixes #855 i tried to reproduce the error but didnt succeed, i think the &nbsp was the result of a previous bug, i also added trim which might have helped.

<pre>

 \begin{exe}
 \ex []{free english the fortuneteller is looking, trying to find out what's going to
 \gll \\
 \\
 \trans }
\label{}
 \begin{description}
 \item[\sc{number}] number
 \item[\sc{cherokee}] cherokee
 \item[\sc{word}] word gloss
 \end{description}
\end{exe}

</pre>