Fix ResourceManager tests on static build.

src/Magnum/Test/ResourceManagerLocalInstanceTestLib.h

@@ -33,6 +33,8 @@
     #else
         #define MAGNUM_RESOURCEMANAGERLOCALINSTANCETESTLIB_EXPORT CORRADE_VISIBILITY_IMPORT
     #endif
+#else
+    #define MAGNUM_RESOURCEMANAGERLOCALINSTANCETESTLIB_EXPORT CORRADE_VISIBILITY_STATIC
 #endif
 
 namespace Magnum { namespace Test {