Can you run the command with a -vvv flag and paste your output here. As a workaround you could try doing the following:
Download memsql server on the host,
debian installation: wget http://release.memsql.com/production/debian/pool/memsql-server_6.8.13_47a99cbc09_amd64.deb
redhat installation: wget http://release.memsql.com/production/rpm/x86_64/memsql-server-6.8.13-47a99cbc09.x86_64.rpm
Re run the memsql-deploy upgrade command with the --file-path <path-to-memsql-server-download>
If you are unable to download this way, it could possible be that the host is unable to access secure sites.