Make the "border" window style be empty
Make the "border" window style be empty

The "border" style set is used by modal attached dialogs in
this version of the Mutter theme. Since their parent window
is faded by the Shell, a visible border doesn't look good.

This case is managed by the "attached" window type in later
versions of the Mutter theme format.

[endlessm/eos-shell#1947]

endlessm/eos-theme