package/qjson: not available for static builds

Fixes:
    http://autobuild.buildroot.org/results/ffa/ffa343702727e118bb98b9c273bd0605de7e75e2/
    http://autobuild.buildroot.org/results/3ca/3ca05b777789c58b0621a100490373416846aa87/
    http://autobuild.buildroot.org/results/a4f/a4f3f9c79731c69082f70c3841c012c576517921/
    ...

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
[Thomas: don't mention the qt4/5 dependency in the comment.]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/qjson/Config.in

@@ -1,8 +1,13 @@
 config BR2_PACKAGE_QJSON
 	bool "qjson"
+	depends on !BR2_STATIC_LIBS
 	depends on BR2_PACKAGE_QT || BR2_PACKAGE_QT5
 	help
 	  QJson is a Qt-based library that maps JSON data to
 	  QVariant objects and vice versa.
 
 	  http://qjson.sourceforge.net
+
+comment "qjson needs a toolchain w/ dynamic library"
+	depends on BR2_STATIC_LIBS
+	depends on !BR2_PACKAGE_QT && !BR2_PACKAGE_QT5