Fix compilation warnings of CHwSMTP

Signed-off-by: Sup Yut Sum <ch3cooli@gmail.com>
Fix compilation warnings of MyGraph.cpp

Signed-off-by: Sup Yut Sum <ch3cooli@gmail.com>
Fix compilation warnings of GitRev.cpp

Signed-off-by: Sup Yut Sum <ch3cooli@gmail.com>
Fix compilation warning of CommitDlg.cpp

Signed-off-by: Sup Yut Sum <ch3cooli@gmail.com>