Revert "Add back GPL license header to iframe.scss"

This reverts commit 401947031b.

src/css/iframe.scss

@@ -1,20 +1,3 @@
-/* 
- * This file is part of EvenBetterSEQTA.
- *
- * EvenBetterSEQTA is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * EvenBetterSEQTA is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with EvenBetterSEQTA.  If not, see <https://www.gnu.org/licenses/>.
- */
-
 body {
   background: transparent;
 }