Issue title: Debian 10.1 and SystemRescue6.0.3 don't boot
 Issue body: I have Debian 9 and Fedora 28 on my laptop. I want update to Debian 10 and Fedora 30.
I used multibootusb when I installed Debian 9 and Fedora 28 from a partition of usb, with SystemRescue 5 and Tails 2.1.
I start multibootusb and uninstall the old distros and install the new distros. The four distros install fine. Fedora 30 and Tails 3.16 boot fine but Debian 10 and SystemRescue 6 don't
Debian 30 was download with bittorrent from http://cdimage.debian.org/debian-cd/current-live/amd64/bt-hybrid/, the sha256sum verified
SystemRescue was download from http://www.system-rescue-cd.org/Download/, the shad256sum verified
I am using multibootusb 9.2.0
Both Debian 10 and SystemRescue 6 say "Undef symbol FAIL: init_fpu" "Failed to load COM32 file libcom32.c32". SystemRescue add "Failed to load COM32 file  wichsys.c32" and Debian add "Failed to load COM32 file vesamenu.c32"
Note: I try with Multisystem too. Debian, Tails and SystemRescue works but Fedora don't. I don't know if that help
 Comments: 
 Comment 0: Same problem here (Debian-case above): 
* ran `mkfs.fat -F 32` on the stick's partition
* MultibootUSB command was:

```bash
sudo python3 multibootusb -c -t /dev/sdb1 \
 -i ../Downloads/gparted-live-1.0.0-5-amd64.iso,../Downloads/clonezilla-live-2.6.3-7-amd64.iso,../Downloads/debian-live-10.1.0-amd64-cinnamon.iso,../Downloads/ubuntu-18.04.3-desktop-amd64.iso
```

Result is as described above.
Reproducible in qemu "Boot USB"
 Comment 1: Same also with Debian Live 10.2.0
 Comment 2: Also same issue with Debian Live 10.3.0 and SystemRescueCD 6.0.7.
 Comment 3: Same with Debian 10.4.0. I tried copying around the syslinux files(as that would have solved the error 
in some cases in the past) but without success. Any insights would be appreciated.
 Comment 4: I found a workaround:

When you're stuck at `boot:`, hit `Tab` and check the possibilities you have. For me I just had to enter `French`, hit `Enter` and the boot went smoothly

Hope that helps

For the record and indexation, here is the full error message I had:

```
Undef symbol FAILED: init_fpu
Failed to load libcom32.c32
Failed to load COM32 file vesamenu.c32
boot:
```
 Comment 5: I [asked for an update of the website]( https://github.com/mbusb/mbusb.github.io/issues/16) as many people seem to face this issue

If you have a few seconds and want to help you may want to submit a PR adding this workaround in the FAQ
 Comment 6: @iootaa I tried this with the net installer iso of Debian. Trying to enter the expert installation by typing "expert" will progress until: 

> Kernel panic - not syncing: No working init found. Try passing init= option to kernel.
{'source': 'GithubIssues', 'repo_name_with_owner': 'mbusb/multibootusb', 'issue_id': 498213812, 'repo_stars': 1383.0}