Merge branch 'openmpi-dlopen' into 'master'

Disable dlopen trick on OpenMPI >= 3.0.0

See merge request walberla/walberla!325

src/python_coupling/helper/ModuleInit.cpp

@@ -26,7 +26,7 @@
 #include "core/debug/CheckFunctions.h"
 
 // Workaround for OpenMPI library: it dynamically loads plugins which causes trouble when walberla itself is a shared lib
-#if defined(OPEN_MPI) && !defined(_WIN32)
+#if defined(OPEN_MPI) && !defined(_WIN32) && OMPI_MAJOR_VERSION < 3
 #define OPEN_MPI_WORKAROUND
 #include <dlfcn.h>
 #endif