Initialize config pointer to nullptr #1038

Job	Run time
Build and Test - Dockerfile	1m 58s
Build and Test - Dockerfile	1m 40s
Build and Test - Dockerfile.memcheck	3m 3s
Build and Test - Dockerfile.memcheck	3m 1s
Build and Test - Dockerfile.fortran-gcc	4m 17s
Build and Test - Dockerfile.fortran-gcc	3m 56s
Build and Test - Dockerfile.openmp	3m 20s
Build and Test - Dockerfile.openmp	2m 31s
Build and Test - Dockerfile.mpi	3m 17s
Build and Test - Dockerfile.mpi	2m 29s
Build and Test - Dockerfile.mpi_openmp	3m 10s
Build and Test - Dockerfile.mpi_openmp	3m 0s
Build and Test - Dockerfile.python	2m 17s
Build and Test - Dockerfile.python	1m 59s
Build and Test - Dockerfile.pip	1m 50s
Build and Test - Dockerfile.pip	1m 59s
	43m 47s

Provide feedback