No empty strings

src/freedombone-controlpanel

         do
             app_index=$[choice-2]
             app_name=${app_list[app_index]}
-            $restore_command "${app_name}"
-            if [ ! "$?" = "0" ]; then
-                dialog --title $"Restore apps from USB" \
-                       --msgbox $"Restore of ${app_name} failed with code $?" 6 40
-                return
+            if [ ${#app_name} -gt 0 ]; then
+                $restore_command "${app_name}"
+                if [ ! "$?" = "0" ]; then
+                    dialog --title $"Restore apps from USB" \
+                           --msgbox $"Restore of ${app_name} failed with code $?" 6 40
+                    return
+                fi
             fi
             ctr=$((ctr + 1))
         done