Fixed lftp exclusion for .git

Fixed the lftp exclusion expression for the .git files:
only the main
- .git
- .git-ftp.log
- .git-ftp-ignore
are being ignored.

This prevents git submodules and files like .gitignore from being ignored but also fixes a problem with files somehow containing the git string.
See the accidentally filed issue here ^^
https://github.com/resmo/git-ftp/issues/226

.git-ftp-ignore might need further investigation. At the moment it would need to contain regular expressions.