Specify timeout for sntp tool

:Release Notes:
Address issue caused by absence of access to NTP server while having
network connection up and running.

:Detailed Notes:
When service tries to request NTP server it does that synchronously
which results in hanging for about 6 minutes without
responding/processing any request (including /time/setBroadcastTime).
Explicitly set timeout in 2 seconds (results in 10 seconds delay) to
minimize effect.
Expect further re-factoring of NTP synchronization mechanisms.

:Testing Performed:
Desktop build.

:QA Notes:

:Issues Addressed:
[GF-55211] luna-sysservice: NTP synchronization blocks service for ~6 minutes

Open-webOS-DCO-1.0-Signed-off-by: Nikolay Orliuk <nikolay.orliuk@lge.com>
Change-Id: I3524208065fc84c442879bdb0cc65ee90c3d07b5
Reviewed-on: https://g2g.palm.com/4179
Reviewed-by: DCO Verification
Reviewed-by: Nikolay Orliuk <nikolay.orliuk@lge.com>
Tested-by: Nikolay Orliuk <nikolay.orliuk@lge.com>
Reviewed-by: Anatolii Sakhnik <anatolii.sakhnik@lge.com>
Reviewed-by: Keith Derrick <keith.derrick@lge.com>