frr: quote 'comment' parameter in Config.in

Newer versions of the kconfig generator require quotes.  Prepare the
package for an eventual update.

Signed-off-by: Eneas U de Queiroz <cotequeiroz@gmail.com>

net/frr/Config.in

@@ -13,6 +13,6 @@ choice
                 bool "internal SSL support"
 endchoice
 
-comment Packages
+comment "Packages"
 
 endif