package/gnuchess: needs c++

Quoted from ChangeLog:

2013-11-23  Antonio Ceballos  <aceballos@gmail.com>
[...]
    * doc/gnuchess.texi: frontend no longer compiled in C; now in C++.

Fixes
http://autobuild.buildroot.net/results/04e/04e7c14c20f0e056e63a712be3821a3f5c94cff1/

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/gnuchess/Config.in

@@ -1,5 +1,6 @@
 config BR2_PACKAGE_GNUCHESS
 	bool "gnuchess"
+	depends on BR2_INSTALL_LIBSTDCPP
 	depends on BR2_TOOLCHAIN_HAS_THREADS
 	select BR2_PACKAGE_FLEX
 	help
@@ -7,5 +8,5 @@ config BR2_PACKAGE_GNUCHESS
 
 	  http://ftp.gnu.org/pub/gnu/chess
 
-comment "gnuchess needs a toolchain w/ threads"
-	depends on !BR2_TOOLCHAIN_HAS_THREADS
+comment "gnuchess needs a toolchain w/ C++, threads"
+	depends on !BR2_INSTALL_LIBSTDCPP || !BR2_TOOLCHAIN_HAS_THREADS