fish_history file permissions

[lakomyt]

File with fish history (~/.local/share/fish/fish_history) has read permission for others. For security reasons it shouldn't be readable for any user.
Even group doesn't need read permission, but that is not so bad.

[faho]

The directory is already 0700, so the file permissions shouldn't really matter all that much.

[zanchey]

Probably a good idea to do though!