Doesn't handle high latency storage well with cbr files

**SumatraPDF version**
SumatraPDF-3.5.2-64.exe

**Describe the bug**
I use sshfs to access storage about 70ms away. 

**Expected behavior**
It should not hang the application for at least thirty minutes.

**File that reproduces the problem**
Batman - The Long Halloween (1998) (digital) (Minutemen-InnerDemons).cbr
I think any over hundred megabyte cbr file would work.
