Fixing AppData Remmina id

Author: antenore

remmina/desktop/appdata.xml

@@ -5,7 +5,7 @@
   Copyright (C) 2016-2017 Antenore Gatta, Giovanni Panozzo.
 -->
 <component type="desktop">
-  <id>org.Remmina.desktop</id>
+  <id>org.remmina.Remmina.desktop</id>
   <metadata_license>CC0-1.0</metadata_license>
   <project_license>GPL-2.0+</project_license>
   <name>Remmina</name>