This dataset appears to have been released just a few days back (20th May) so it may not be fully ready to download from ENA.
$ curl -L ftp://ftp.sra.ebi.ac.uk/vol1/fastq/SRR163/098/SRR16351998/SRR16351998.fastq.gz -o SRR16351998_GSM5627759_DU145_A6_clone-empty_vector_control_1_Homo_sapiens_RNA-Seq.fastq.gz
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0
curl: (9) Server denied you to change to the given directory
You may simply need to try after a time.
I was able to download from NCBI using fastq-dump. So you could go that route if you need the data now.