Nathan Lanza 27b52acee7 Only attempt to use dirvish if b:dirvish exists ...

This was causing persistent errors when you run, for example,

```
ls | nvim -c 'setf dirvish'
```

as dirvish will not yet have set that local variable yet airline will
attempt to use it.

2020-09-15 12:30:27 +02:00

..

airline

Only attempt to use dirvish if b:dirvish exists

2020-09-15 12:30:27 +02:00

airline.vim

mode: keep hi setting when switching from 'n' to 'ni'

2020-08-26 22:46:05 +02:00