"Ignore this prompt forever" from ionic login is not working

**Description:**
I have multiple Pro accounts (and projects) and I'm everytime switching among them. This is a bit tedious and I'd like find a way to keep up my session for every project, but that's another thing... The issue here is that the prompt asking me about "How would you like to connect to Ionic Pro?" is ignoring the selected option "Ignore this prompt forever":
```
$ ionic login
[WARN] Detected locally installed Ionic CLI, but it's too old--using global CLI.
[WARN] You are already logged in as user1@example.com! Prompting for new credentials.

? Email: user2@example.com

? Password: [hidden]
Logging you out.
> ionic logout
[OK] You are logged out.
[OK] You are logged in!
> ionic ssh setup
Looks like you haven't configured your SSH settings yet.

? How would you like to connect to Ionic Pro? Ignore this prompt forever
[OK] We won't pester you about SSH settings anymore!
```
It is not detecting that I already have done through this (detection issue might be related to https://github.com/ionic-team/ionic-cli/issues/2829) and it continues asking me for Ionic Pro connecting everytime regardless of the provided answer.

**Steps to Reproduce:**
1. Login with an Ionic Pro account (user1@example.com). Answer "Ignore this prompr forever" to "How would you like to connect to Ionic Pro?".
2. Login with another Ionic Pro account (user2@example.com). Answer "Ignore this prompr forever" to "How would you like to connect to Ionic Pro?".
3. Login back with user1@example.com and it will ask again for Ionic Pro connecting regardless of the selected answer.

**My `ionic info`:**
```
cli packages: (/home/shamank/.nvm/versions/node/v8.2.1/lib/node_modules)

@ionic/cli-utils : 1.15.2
ionic (Ionic CLI) : 3.15.2

global packages:

cordova (Cordova CLI) : 7.1.0

local packages:

@ionic/app-scripts : 3.0.1
Cordova Platforms : android 6.2.3 browser 5.0.1 ios 4.4.0
Ionic Framework : ionic-angular 3.8.0

System:

Android SDK Tools : 26.1.1
Node : v8.2.1
npm : 4.6.1
OS : Linux 3.19

Environment Variables:

ANDROID_HOME : /home/shamank/Android/Sdk

Misc:

backend : pro
```

透過 `ionic login` 和 `ionic ssh setup`，在步驟中描述的兩個帳戶之間切換，以重現該行為。追蹤「永遠忽略此提示」選項如何在帳戶之間持久化並被偵測，然後驗證返回某個帳戶時不再提示 Ionic Pro 連線設定。

由索引模型根據 Issue 內容生成。