Fix #4259 - Failure to parse ANSI codes for msf prompt on Winodws

Fix #4259.

On Windows, the msf prompt is unable to parse and render the color codes. It also causes the prompt to be almost unusable, as in you can't really see what you type. So this fix will not use ANSI codes for the default prompt for Windows.

Also:
* Kali doesn't seem to be affected by this.
* Only the msf prompt is having this issue. Other parts that use ANSI codes seem to be working fine.

## For users who are currently experiencing this issue ##

If you see stuff like ```<[ 4m<-[0m<-[36mmsf-pro``` on your console .... know that this fix does not actually fix that particular prompt. Instead, that is a Pro-specific prompt (not framework), so you will have to wait for Pro's fix to merge.

While waiting for the patches to be merged, as an user you can do the following at your prompt as a temporary workaround:

```
color false
```