Trade: explicitly link tests to CORRADE_PLUGINMANAGER_LIBRARIES.

Compilation of tests in static build fails with missing
reference to dlclose().

src/Trade/Test/CMakeLists.txt

@@ -27,8 +27,8 @@ configure_file(${CMAKE_CURRENT_SOURCE_DIR}/testConfigure.h.cmake
 
 include_directories(${CMAKE_CURRENT_BINARY_DIR})
 
-corrade_add_test(TradeAbstractImageConverterTest AbstractImageConverterTest.cpp LIBRARIES Magnum)
-corrade_add_test(TradeAbstractImporterTest AbstractImporterTest.cpp LIBRARIES Magnum)
+corrade_add_test(TradeAbstractImageConverterTest AbstractImageConverterTest.cpp LIBRARIES Magnum ${CORRADE_PLUGINMANAGER_LIBRARIES})
+corrade_add_test(TradeAbstractImporterTest AbstractImporterTest.cpp LIBRARIES Magnum ${CORRADE_PLUGINMANAGER_LIBRARIES})
 corrade_add_test(TradeAbstractMaterialDataTest AbstractMaterialDataTest.cpp LIBRARIES Magnum)
 corrade_add_test(TradeImageDataTest ImageDataTest.cpp LIBRARIES Magnum)
 corrade_add_test(TradeObjectData2DTest ObjectData2DTest.cpp LIBRARIES Magnum)