Revert "specificy the toolchain ppa for each gcc or clang version"
Revert "specificy the toolchain ppa for each gcc or clang version"

This reverts commit 7c2cfd8676dd92a3574eb22d61d2d2a06608e702.

accosmin/nanocv,accosmin/nanocv,accosmin/nano,accosmin/nanocv,accosmin/nano,accosmin/nano