Setup Toolchains for clang on Linux does not work

For setup I run:

qbs setup-toolchains --type clang /usr/bin/clang++ myProfile

This worked great with Qbs 1.24.0 and fails after updating to Qbs 2.1.2.

When I use the generated profile the `g++` compiler is used.

As a workaround I run:

qbs config profiles.myProfile.cpp.compilerName "clang++"
qbs config profiles.myProfile.cpp.cxxCompilerName "clang++"
qbs config profiles.myProfile.cpp.cCompilerName "clang"

It seems like the `myProfile.qbs.toolchainType=clang` no longer works as expected.