#2171 installer will stay in "is being executed." state

[Alexander Stohr]

the win32 installer panel will gray out progress bars after completion but the text above that all will remain "Executing - The main task is beeing executed."
those two parts are vice versa exclusive and should not show up at the very the same time.
change this to improve the quality the end user is offered whilst installtion - else he is unsure if installation is really done now.