[bug] No message if TAURI_KEY_PASSWORD env is missing for build

[brys0]

Describe the bug

Theres no message pretaining if TAURI_KEY_PASSWORD doesn't exist. It just has it display:

thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: PError { kind: Verify, err: "Wrong password for that key" }', C:\Users\USER\.cargo\registry\src\github.com-1ecc6299db9ec823\tauri-cli-1.0.0-rc.4\src\helpers\updater_signature.rs:113:51

Reproduction

1. Create sig

Expected behavior

It should tell you that there is no tauri_key_password set. Or, better yet, prompt if it doesn't exist and warn for the future.

Platform and versions

All

Stack trace

Bundling "C:\\Users\\bryso\\Desktop\\chatty-desktop-v2\\src-tauri\\target\\release\\bundle/msi/chatty_0.0.2_x64_en-US.msi.zip"
    Finished 2 bundles at:
        C:\Users\bryso\Desktop\chatty-desktop-v2\src-tauri\target\release\bundle/msi/chatty_0.0.2_x64_en-US.msi
        C:\Users\bryso\Desktop\chatty-desktop-v2\src-tauri\target\release\bundle/msi/chatty_0.0.2_x64_en-US.msi.zip (updater)
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: PError { kind: Verify, err: "Wrong password for that key" }', C:\Users\bryso\.cargo\registry\src\github.com-1ecc6299db9ec823\tauri-cli-1.0.0-rc.4\src\helpers\updater_signature.rs:113:51
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
error Command failed with exit code 101.

Additional context

Using tauri-cli = "1.0.0-rc.4"