Moved 'git_askpass' shell script to product/ERP5/bin (considering that this
is a very short shell script which hasn't changed in 7 years, no need to move
it to the ZODB which would require creating a temporary file...).

After updating erp5_forge, you should delete 'product/ERP5VCS/' directory
as this will only contain '.pyc' files.

/reviewed-on !973