Theorems and the like are not translated if the current language is other than English

[dbitouze]

Theorems and the like are not translated if the current language is other than English. E.g. the following MCE:

\documentclass[french]{nwejmart}
\begin{document}
\begin{theorem}
  Foo
\end{theorem}
\end{document}

leads to "Theorem 1 – Foo" instead of "Théorème 1 – Foo".