Remove unused bgp-update-api-config

bgp-update-api-config.jar has been long empty, so we do not need to
include it in the distribution anymore.

Change-Id: I30435efb0996cffb1aaad20637d762814ca75c1a
Signed-off-by: Robert Varga <rovarga@cisco.com>
(cherry picked from commit cd2b8c1aad9289b88f5309e6a3657d432270ee69)