Fix missing semicolon in `gcf` function

Adding this semicolon does not fix any compilation issue
but why the first line has one whereas the second one does not.
In fact, it also fixes an incorrect syntax highlighting
from SCSS.tmbundle in Sublime Text.
It is great.
Merge pull request #23 from 7studio/fix-gcf-semicolon

Fix missing semicolon in `gcf` function