fix: Unable to use config value to set smtp_port in email action configuratio...

[Roshan931]

Fixes #542

Root cause

email plugin validates smtp_port/smtp_skip_tls_verify before template evaluation

Changes

• Skip the strconv strict-parse checks in the email plugin's validConfig when the value still contains a template handle (same convention already used by the http and apiovh plugins), and move the real parsing errors to exec so an invalid runtime-templated value fails the step instead of being silently coerced to 0/false. Added unit tests covering templated and invalid values.