Can't load file on windows 7

When I try to do C-c C-l, it fails with the following error

```
haskell-process-cmd-queue-add: Wrong type argument: haskell-command, [cl-struct-haskell-command ((name . "haskell") (inferior-process . #) (is-restarting) (current-command) (suggested-imported) (sent-stdin) (evaluating) (session (name . "haskell") (current-dir . "c:/Users/Ognjen/Desktop/") (target . "") (cabal-checksum) (cabal-dir . "c:/Users/Ognjen/Desktop/") (process (name . "haskell") (inferior-process . #) (is-restarting) (current-command) (suggested-imported) (sent-stdin) (evaluating) #2))) #[257 "Â
ÃÄÅÆ…\0Ç\"È#\"ˆÂ
É\"ˆÂ
ÊË \"\"‡" [haskell-interactive-set-+c haskell-interactive-prompt2 haskell-process-send-string mapconcat identity append ("Prelude.putStrLn \"\"" ":set -v1") (":set +c") "
" ":set prompt \"\\4\"" ...] 8 "

(fn PROCESS)"] #[514 "ÀÁ\"…*\0ÂÃ\"ÄÅ!ÆÇÈÉÊË!Ì\"ÍÎ%#ˆÏÅ!ÐÑ\"\"²
‡" [haskell-process-consume "^*** WARNING: \\(.+\\) is writable by someone else, IGNORING!$" match-string 1 haskell-session-modify haskell-process-session ignored-files make-byte-code 257 "ÁÀBÂÃ#‡" ...] 12 "

(fn PROCESS BUFFER)"] #[514 "ÃÄ!ÅG!8 …\0ÆP\"ˆrÇ qˆ
b)‡" [haskell-process-greetings haskell-process-show-debug-tips haskell-interactive-mode-prompt-start haskell-interactive-mode-echo haskell-process-session random "
If I break, you can:
1. Restart: M-x haskell-process-restart
2. Configure logging: C-h v haskell-process-log (useful for debugging)
3. General config: M-x customize-mode
4. Hide these tips: C-h v haskell-process-show-debug-tips" haskell-interactive-buffer] 6 "

(fn PROCESS _)"]], cmd
```

If I do C-c C-l again, the interactive window is opened, but every expression that I enter is ignored. If you press enter once nothing happens, if you press it twice you get a new line and can enter a new expression.

This is my relevant config:

```
(use-package haskell-mode
:config
(setq haskell-process-suggest-remove-import-lines t)
(setq haskell-process-auto-import-loaded-modules t)
(setq haskell-process-log t)
(setq haskell-process-type 'cabal-repl))
(require 'haskell-interactive-mode)
(require 'haskell-process)
(add-hook 'haskell-mode-hook 'interactive-haskell-mode)
```
I should also note that cabal repl is started successfully (after I try to load the file twice). My file is even successfully complied. I can confirm that by looking at the haskell-process-log.

My system:
- Window 7 (sorry :D)
- GHC 8.2.2
- Emacs 26.1
- haskell-mode 20180601.143

Reproduce C-c C-l using the reported Windows 7, GHC, Emacs, and haskell-mode versions with the supplied configuration, then inspect the haskell-process-cmd-queue-add failure. Done means the file loads successfully on the first attempt and expressions entered in the interactive window are evaluated normally.

Written by the indexing model from the issue text.