[native] fix error alert detail casing in AddKeyserver

Summary: I landed D12058 to fix error alert casing but looks like in D12057 there was one alert that was just very recently introduced that I didn't pull down + update causing eslint ci to fail. This diff should fix that

Test Plan: flow

Reviewers: will, ashoat

Reviewed By: will

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D12059