libcgicc: depend on toolchain config, don't use select

select should only be used for package (library) dependencies.

package/libcgicc/Config.in

@@ -1,8 +1,11 @@
 config BR2_PACKAGE_LIBCGICC
 	bool "libcgicc"
-	select BR2_INSTALL_LIBSTDCPP
+	depends on BR2_INSTALL_LIBSTDCPP
 	help
 	  GNU cgicc is a C++ class library that greatly simplifies
 	  the creation of CGI applications for the World Wide Web.
 
 	  http://www.cgicc.com
+
+comment "libcgicc requires a toolchain with C++ support enabled"
+	depends on !BR2_INSTALL_LIBSTDCPP