Fixes LSAN reports:
```
Indirect leak of 7480 byte(s) in 55 object(s) allocated from:
    #0 0x7f45be2abf41 in operator new(unsigned long) /build/gcc/src/gcc/libsanitizer/asan/asan_new_delete.cpp:99
    #1 0x7f45b148435a in QThread::QThread(QObject*) (/usr/lib/libQt5Core.so.5+0xcc35a)

Indirect leak of 6600 byte(s) in 55 object(s) allocated from:
    #0 0x7f45be2abf41 in operator new(unsigned long) /build/gcc/src/gcc/libsanitizer/asan/asan_new_delete.cpp:99
    #1 0x7f45b14843bf in QThread::QThread(QObject*) (/usr/lib/libQt5Core.so.5+0xcc3bf)

Indirect leak of 5280 byte(s) in 55 object(s) allocated from:
    #0 0x7f45be2abf41 in operator new(unsigned long) /build/gcc/src/gcc/libsanitizer/asan/asan_new_delete.cpp:99
    #1 0x7f45b148be25 in QWaitCondition::QWaitCondition() (/usr/lib/libQt5Core.so.5+0xd3e25)

Indirect leak of 880 byte(s) in 55 object(s) allocated from:
    #0 0x7f45be2abf41 in operator new(unsigned long) /build/gcc/src/gcc/libsanitizer/asan/asan_new_delete.cpp:99
    #1 0x55ef2619f72a in KDevelop::TestForegroundLock::testTryLock() /home/milian/projects/kf5/src/extragear/kdevelop/kdevelop/kdevplatform/util/tests/test_foregroundlock.cpp:73
```