Remove wengophone from arm arch, please

[Ludovico Cavedon <cavedon@sssup.it>]

Hi,
the package wengophone started failing build on arm architecture because
of an internal compiler error of gcc.

This is blocking wengophone migration to testing. Could you please
remove wengophone from arm architecture?
In the meanwhile I'll ask the support of the arm team for solving the
problem on that arch.

Thank you,
Regards,
Ludovico