Fix tst_qsql crashes on Mac OS X

Fix tst_qsql crashes on Mac OS X

In tst_qsql, there are function calls to  QApplication(argc, 0, false), where
argc is zero. According to the documentation, argc must be greater than
zero and argv must contain at least one valid character string. The
misuse of this API has no problem on any platform other than Mac OS. This
commit has fixed the crash by passing valid dummy parameters.

Task-number: QTBUG-22811
Change-Id: I42b26d66f0becb7a942896e6ddcaea52ff720a48
Reviewed-by: Bradley T. Hughes <bradley.hughes@nokia.com>