Fixes LSAN report:

```
Indirect leak of 16 byte(s) in 1 object(s) allocated from:
    #0 0x7fbbce16ef41 in operator new(unsigned long) /build/gcc/src/gcc/libsanitizer/asan/asan_new_delete.cpp:99
    #1 0x56469f8deab5 in KDevMI::GDB::DebugSession::execInferior(KDevelop::ILaunchConfiguration*, IExecutePlugin*, QString const&) /home/milian/projects/kf5/src/extragear/kdevelop/kdevelop/plugins/gdb/debugsession.cpp:217
    #2 0x56469fa482f2 in KDevMI::MIDebugSession::startDebugging(KDevelop::ILaunchConfiguration*, IExecutePlugin*) /home/milian/projects/kf5/src/extragear/kdevelop/kdevelop/plugins/debuggercommon/midebugsession.cpp:284
    #3 0x56469f81ef97 in KDevMI::GDB::GdbTest::testRemoteDebug() /home/milian/projects/kf5/src/extragear/kdevelop/kdevelop/plugins/gdb/unittests/test_gdb.cpp:1658
```