g10: Suppress error for card availability check.
* g10/call-agent.c (start_agent): Add semantics for card; Suppress error for card check. (warn_version_mismatch): Ignore an error for scdaemon. (agent_scd_serialno): Call start_agent with FLAG_FOR_CARD_SUPPRESS_ERRORS.
- GnuPG-bug-id: T3165
- Fixes-commit: 97a2394ecafaa6f58e4a1f70ecfd04408dc15606
- Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>