Question / Problem:
In Roles.xml, under resourcesTabPermission, we do not see:
<property name="addConnector" value="true"/>
<property name="deleteConnector" value="true"/>
Answer / Solution:
This is a Bug: Bug 1492940:Add/Delete Connector properties are missing in roles.xml
It was reported in 220.127.116.11 and it was fixed in 11.1
Add the 2 lines manually in roles.xml.
Adding this manually to the code (and setting it to false) allows preventing some users from uploading connectors into management console.