[CLAMP] Refer to docker.io mariadb

Remove the link to cached mariadb in nexus3.onap.org, use docker.io instead

Issue-ID: CLAMP-855
Signed-off-by: sebdet <sebastien.determe@intl.att.com>
Change-Id: I449298ae0188d1478cf4ae13383c00c5e921de88
1 file changed