cli/command: PromptUserForCredentials: always trim password

we don't support empty passwords; when prompting the user for a password,
we already trim the result, but we didn't do the same for a password that's
passed through stdin or through the `-p` / `--password` flag.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

cli/command/registry.go

@@ -155,6 +155,7 @@ func PromptUserForCredentials(ctx context.Context, cli Cli, argUser, argPassword
 		}
 	}
 
+	argPassword = strings.TrimSpace(argPassword)
 	if argPassword == "" {
 		restoreInput, err := DisableInputEcho(cli.In())
 		if err != nil {