extra_build_tools is used as an array in build_tools.py but defined as a dict

Submitted by Stephane Cerveau

Link to original bug (#797031)

Description

Created attachment 373462
Patch initializing extra_build_tools to an array

The extra_build_tools config variable is initialized a dict but used as an array in build_tools.py

Patch 373462, "Patch initializing extra_build_tools to an array":
0001-extra_build_tools-should-be-initialized-to-an-array.patch