Add more try/finally in DotCover
Add more try/finally in DotCover

The problem is the same for other test runners than NUnit so the same fix
is now applied.

Kazark/FAKE,RMCKirby/FAKE,beeker/FAKE,rflechner/FAKE,mglodack/FAKE,beeker/FAKE,RMCKirby/FAKE,MiloszKrajewski/FAKE,RMCKirby/FAKE,mglodack/FAKE,rflechner/FAKE,mglodack/FAKE,Kazark/FAKE,Kazark/FAKE,MichalDepta/FAKE,beeker/FAKE,MiloszKrajewski/FAKE,RMCKirby/FAKE,beeker/FAKE,rflechner/FAKE,Kazark/FAKE,MichalDepta/FAKE,MichalDepta/FAKE,MiloszKrajewski/FAKE,MichalDepta/FAKE,MiloszKrajewski/FAKE,rflechner/FAKE,mglodack/FAKE