[Qt-creator] Minor bug, Makefile not regen

[alpha_one_x86]

Hello, when I switch my folder between windows and linux, when all is
clean no problem.
But when .o is genered that's bug (normal) Qt creator should detect the
last platform used for clean the .o if needed.
When I click on "Clean" the Makefile is not regen then I need click on
"Build" for bug but regen the Makefile for only after do "Clean"