fix missing quote (thx, puchu)

SVN-Revision: 19335

package/base-files/image-config.in

@@ -81,7 +81,7 @@ config TARGET_PREINIT_NETMASK
 config TARGET_PREINIT_BROADCAST
        string
        prompt "Broadcast address for preinit network messages" if PREINITOPT
-       default "192.168.1.255
+       default "192.168.1.255"
        help
 		Broadcast address to which to send preinit network messages, as
 		as failsafe messages