Panic at src/git.rs:64:60 for file names with invalid chars

- os: Linux
- `lsd --version`: lsd 1.0.0
- `echo $TERM`: tmux-256color
- `echo $LS_COLORS`:
- commit: 6f8e0952

## Expected behavior

Don't panic.

## Actual behavior

```
$ mkdir test
$ cd test
$ git init
$ touch $'\xee'
$ lsd
 �
$ lsd -lg
thread 'main' panicked at src/git.rs:64:60:
called `Option::unwrap()` on a `None` value
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
```

Start in src/git.rs at line 64, then reproduce the panic in a Linux terminal with a filename containing invalid characters and the lsd -lg command shown in the report. Trace the unwrap that receives no value and verify that lsd -lg lists the file without panicking.

Written by the indexing model from the issue text.