Update README.md (#349)

fix typo in README

Author: Totto16

README.md

@@ -96,7 +96,7 @@ Since Gnome 45 we had to break compatibility with previous Gnome versions, these
 - Gnome Shell 46
 - Gnome Shell 47
 - Gnome Shell 48
-- 
+
 ## Installation
 
 - You need `libgda` and `gsound` for this extension to work.