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

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.

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:
If you see stuff like <[ 4m<-[0m<-[36mmsf-pro on your console .... know that this fix does not actually fix that. Instead, that is a Pro-specific prompt (not framework), so you will have to wait for Pro's fix to merge.

Fix #4259.