Improve instructions about how to upload image streams of amq, ... using system user

[cmoulliard]

The user system can't create image stream when we issue this command

oc create -f openshift-ansible/roles/openshift_examples/files/examples/v1.2/xpaas-streams/jboss-image-streams.json -n openshift
Error from server: User "system" cannot create imagestreams in project "openshift"
Error from server: User "system" cannot create imagestreams in project "openshift"
Error from server: User "system" cannot create imagestreams in project "openshift"
Error from server: User "system" cannot create imagestreams in project "openshift"
Error from server: User "system" cannot create imagestreams in project "openshift"
Error from server: User "system" cannot create imagestreams in project "openshift"
Error from server: User "system" cannot create imagestreams in project "openshift"

but well as such

oc login -u system https://10.1.2.2:8443
You don't have any projects. You can try to create a new project, by running

    $ oc new-project <projectname>

oc new-project amq
Now using project "amq" on server "https://10.1.2.2:8443".
oc create -f openshift-ansible/roles/openshift_examples/files/examples/v1.2/xpaas-streams/jboss-image-streams.json
imagestream "jboss-webserver30-tomcat7-openshift" created
imagestream "jboss-webserver30-tomcat8-openshift" created
imagestream "jboss-eap64-openshift" created
imagestream "jboss-decisionserver62-openshift" created
imagestream "jboss-processserver62-openshift" created
imagestream "jboss-datagrid65-openshift" created
imagestream "jboss-amq-62" created

[christian-posta]

Think you need to use oc login -u system:admin 10.0.2.15:8443