package/kismet: server needs wchar

kismet embeds its own copy of fmt since version 2019-04-R1 so add a
dependency on wchar to avoid the following build failure when building
the server:

./fmt/core.h:1245:1:
 std::wstring vformat(wstring_view format_str, wformat_args args);
 ^~~
./fmt/core.h:1266:13: error: 'wstring' in namespace 'std' does not name a type
 inline std::wstring format(wstring_view format_str, const Args & ... args) {
             ^~~~~~~
./fmt/core.h:1266:8: note: 'std::wstring' is defined in header '<string>'; did you forget to '#include <string>'?

Fixes:
 - http://autobuild.buildroot.org/results/f19b3d080514a799a1c75b38ff5f7ae4e8d2628d

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

package/kismet/Config.in

@@ -59,14 +59,16 @@ config BR2_PACKAGE_KISMET_SERVER
 	default y
 	depends on BR2_PACKAGE_PROTOBUF_ARCH_SUPPORTS # protobuf
 	depends on !BR2_STATIC_LIBS # dlfcn.h
+	depends on BR2_USE_WCHAR
 	depends on BR2_TOOLCHAIN_GCC_AT_LEAST_4_8 # protobuf
 	depends on !BR2_TOOLCHAIN_HAS_GCC_BUG_64735 # std::future
 	select BR2_PACKAGE_PROTOBUF
 
-comment "server needs a toolchain w/ dynamic library, gcc >= 4.8"
+comment "server needs a toolchain w/ dynamic library, wchar, gcc >= 4.8"
 	depends on BR2_PACKAGE_PROTOBUF_ARCH_SUPPORTS
 	depends on !BR2_TOOLCHAIN_HAS_GCC_BUG_64735
-	depends on BR2_STATIC_LIBS || !BR2_TOOLCHAIN_GCC_AT_LEAST_4_8
+	depends on BR2_STATIC_LIBS || !BR2_USE_WCHAR || \
+		!BR2_TOOLCHAIN_GCC_AT_LEAST_4_8
 
 comment "server needs a toolchain not affected by GCC bug 64735"
 	depends on BR2_TOOLCHAIN_HAS_GCC_BUG_64735