Fix slc5-gcc46 compilation on slc6
Because of the way custom builds of GCC treat system headers, the version of gcc 4.6 we use to build slc5-gcc46 binaries fails on slc6 system headers.
This minor changes fix the compilation (see http://readlist.com/lists/gcc.gnu.org/gcc-help/4/21431.html for details)
Edited by Marco Clemencic