zxing-cpp: needs dynamic library

Fixes:
http://autobuild.buildroot.net/results/982/982bd00de9da8cedd47209ece4fac92bbcccb04b/

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/zxing-cpp/Config.in

@@ -1,8 +1,9 @@
-comment "zxing-cpp needs a toolchain w/ C++"
-	depends on !BR2_INSTALL_LIBSTDCPP
+comment "zxing-cpp needs a toolchain w/ C++, dynamic library"
+	depends on !BR2_INSTALL_LIBSTDCPP || BR2_STATIC_LIBS
 
 config BR2_PACKAGE_ZXING_CPP
 	bool "zxing-cpp"
+	depends on !BR2_STATIC_LIBS
 	depends on BR2_INSTALL_LIBSTDCPP
 	help
 	  ZXing-cpp (pronounced "zebra crossing") is an open-source,