package_deb: Fix python runtime error

package_deb: Fix python runtime error

The dictionary cannot be used for iteration if its size may change
during the loop.

ERROR: Error executing a python function in
/home/ricardo/curro/qt5022/build-qt5022/repo/yocto/meta/recipes-devtools/perl/perl_5.22.0.bb:
Exception: RuntimeError: dictionary changed size during iteration

Acked-by: Aníbal Limón <anibal.limon@linux.intel.com>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>