I could send you the file again if you like, but the easier way would be to:
-If you have any other mods, download FH AGAIN but call it Feral-Heart.
-Then you will have the normal sky; and then you just have to paste in the rest of the mods (if you have any other ones that you would like to keep) from the old folder into the new one.
Just don't paste in the nebula sky. xD
Hope this helps.