fix regex to match memcheck timing
fix another matching problem because of mixed stdout/stderr
make another attempt to set the test configuration type

Other tests do the same, although I don't understand what's going on here.
Let's see if it works ;)
Merge topic 'MemChecker-improvements' into next

4ee4934 make another attempt to set the test configuration type
5d8a6d1 fix another matching problem because of mixed stdout/stderr
18ae1cc fix regex to match memcheck timing