Respect the mixing EOL when review patch with TortoiseGitMerge

The steps:
1. Invoke "Apply Patches" dialog
2. Add a patch with mixing CRLF(line 1) and LF(line 2)
3. Right click on that patch in list
4. Click Review Patch with TortoiseGitMerge
5. The EOL of Line 2 is CRLF (should be LF)

Signed-off-by: Yue Lin Ho <b8732003@student.nsysu.edu.tw>