Description of problem:
I have set in /etc/imapd.conf "altnamespace: yes" yet I am still seeing all of my folders as children of INBOX.

Version-Release number of selected component (if applicable):
cyrus-imapd-2.4.17-8.el7_1

How reproducible:
100%

Steps to Reproduce:
1. Install and configure cyrus-imapd
2. Set "altnamespace: yes" in /etc/imapd.conf
3. Open IMAP account in evolution

Actual results:
Inbox has all folders as children

Expected results:
Folders should be at the same level as Inbox

Additional info:
From https://cyrusimap.org/docs/cyrus-imapd/2.4.7/altnamespace.php:

Alternate Mailbox Namespace

The alternate namespace allows a user's personal mailboxes to appear as if they reside at the same level as that user's INBOX as opposed to children of it. For example, if user "bovik" had a personal "work" mailbox, it would appear to user "bovik" as "work" instead of "INBOX.work" as it would in the standard namespace.
This configuration requires that a special prefix be used for shared folders (to distinguish them from personal folders) and for accessing other users' folders. By default, the prefix for shared folders is "Shared Folders" and the prefix for other users folders is "Other Users". For example, a shared folder "foo" in the standard namespace would be presented as "Shared Folders.foo" in the alternate namespace.
NOTE: All tools for administering the server, including admins using cyradm, always use the internal namespace.
Configuring the Alternate Namespace

To use the alternate namespace, turn on the altnamespace option in /etc/imapd.conf. The prefixes used for shared folders and other users folders can be changed from the defaults by setting the sharedprefix and userprefix options respectively.

My /etc/imapd.conf:

configdirectory: /var/lib/imap
partition-default: /var/spool/imap
admins: cyrus brian
sievedir: /var/lib/imap/sieve
sendmail: /usr/sbin/sendmail
hashimapspool: true
sasl_pwcheck_method: saslauthd
sasl_mech_list: LOGIN GSSAPI PLAIN
allowplaintext: no
defaultdomain: mail
tls_cert_file: /etc/pki/cyrus-imapd/cert.pem
tls_key_file: /etc/pki/cyrus-imapd/privkey.pem
tls_ca_file: /etc/pki/cyrus-imapd/fullchain.pem
altnamespace: yes
autocreatequota: 0
lmtp_downcase_rcpt: yes
sasl_keytab: /etc/krb5_cyrus.keytab
autocreate_post: 1