Fix compilation warning of Git.cpp

Signed-off-by: Sup Yut Sum <ch3cooli@gmail.com>
[WIP] Fixed issue #2168: Add to the "Clean up" dialog "Recursive" option for submodules

Current implementation of submodule files cleanup does not support the use of recycle bin

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