Fix a bug where Phortune accounts created via "Create Account" would not have the viewer added as a member

Summary:
Ref T12451. When you explicitly created a second or third account or whatever, you wouldn't be added as a member.

(The editor sees that you're "already a member", so it doesn't add you.)

Test Plan:

• Go to /phortune/.
• Click "Switch Accounts".
• Click "Create Account".
• Create an account.
• Before patch: unable to view it since you don't get added as a member.
• After patch: account created with you as member.
• Also created an accont with multiple members.
• Tried to create an account with no members.
• Tried to create an account with just someone else as a member.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T12451

Differential Revision: https://secure.phabricator.com/D17690