please drop build-dependency on g++-4.9

[Steve Langasek]

The dbus-cpp package currently has a build-dependency on g++-4.9. This build-dependency is present because of the recommendations on https://wiki.ubuntu.com/cpp-11 about handling of C++11.

The C++11 ABI has now stabilized in gcc as of gcc 5; however, before we can switch to gcc 5, we first need to be able to do rebuild tests of the archive against this compiler.

To facilitate this, please drop the build-dependency on g++-4.9 from the package in wily. 4.9 will remain the default until all transition issues have been identified, so there is no risk of accidental ABI breakage here anymore.

[Matthias Klose (doko)]

confirmed, prevents building in the silo 16 with GCC 5.

[Matthias Klose (doko)]

now fixed in silo16