fix: remove unnecessary if condition

[CaptainOfPhB]

Problem
nrm ls and nrm current can not display the current registry.

Bug
hasOwnProperty(customRegistries, name) is always false after nrm use taobao(for example), so the statement registry[FIELD_IS_CURRENT] = true; can not be executed forever.

Description
name in allRegistries is already judged in L186, allRegistry include customRegistry and registries, so the if condition in L211 is unnecessary.

Fix: #101
Fix: #109
Fix: #110

[CaptainOfPhB]

@i5ting

[i5ting]

@CaptainOfPhB 补一下测试用例

[CaptainOfPhB]

@CaptainOfPhB 补一下测试用例

@i5ting 这个库没有单测呀😂

[xiaoyu-666]

呃，我没看到这次提交

[i5ting]

@CaptainOfPhB 加一个uvu或tap做测试吧，撸起来

[xiaoyu-666]

@CaptainOfPhB 加一个uvu或tap做测试吧，撸起来
如果这个if条件判断去掉后，
还有一个问题也能复发这个没有星号的问题，就是本机是windows系统，安装了wsl子系统，两个系统都安装了npm，wsl子系统npm的/hone/用户名/.npmrc配置文件会被本机windows系统中C:\Users\用户名\.npmrc的配置文件覆盖，这时候wsl子系统使用nrm use taobao都会失效，只要删除本机windows系统中npm的配置文件即可恢复正常