Updated desktop file to no longer pass useless argument

data/org.postmarketos.Megapixels.desktop

@@ -1,6 +1,6 @@
 [Desktop Entry]
 Name=Megapixels
-Exec=megapixels /etc/megapixels.ini
+Exec=megapixels
 Terminal=false
 Type=Application
 Categories=GTK;