bts-sysmo: Replace use of deprecated ipa_client_conn_create API
bts-sysmo: Replace use of deprecated ipa_client_conn_create API

"""
osmo-bts/src/osmo-bts-sysmo/misc/sysmobts_mgr_calib.c:544:9: warning:
‘ipa_client_conn_create’ is deprecated: Use ipa_client_conn_create2()
instead [-Wdeprecated-declarations]
"""

Change-Id: Ief4d629f366e4f69ccd489198302568a919b2f0c

osmocom/osmo-bts,osmocom/osmo-bts,osmocom/osmo-bts