Update klayout.desktop for gnome GNOME DE

"Open filetype with" dialogs now offer klayout as an option.

Author: mikeyh30

etc/klayout.desktop

@@ -3,7 +3,7 @@ Version=1.0
 Name=Klayout, viewer and editor of mask layouts.
 GenericName=layout viewer
 Comment=Klayout is a viewer (and editor) of mask layout in a.o. GDSII and CIF format.
-Exec=klayout
+Exec=klayout %f
 Icon=klayout
 Type=Application
 Categories=Development;Engineering;Electronics;