ice: disable aggressive nomination

ICE "aggressive nomination" was enabled to reduce connection time.
However, this feature may cause ICE to nominate a sub-optimal pair
during the negotiation process. For example, nominating a
relay-prflx pair, while a srflx-prflx is more optimal.
Furthermore, aggressive nomination was dropped in the latest ICE
specification (RFC-8445)
Also fix logging of nominated pairs

Gitlab: #601

Change-Id: Ib08103b830fc0c5d158cf776a1082a0655317270