p2p: remove obsolete local time in handshake

Also removes a potential fingerprinting vector

src/p2p/net_node.inl

@@ -1918,9 +1918,6 @@ namespace nodetool
   template<class t_payload_net_handler>
   bool node_server<t_payload_net_handler>::get_local_node_data(basic_node_data& node_data, const network_zone& zone)
   {
-    time_t local_time;
-    time(&local_time);
-    node_data.local_time = local_time; // \TODO This can be an identifying value across zones (public internet to tor/i2p) ...
     node_data.peer_id = zone.m_config.m_peer_id;
     if(!m_hide_my_port && zone.m_can_pingback)
       node_data.my_port = m_external_port ? m_external_port : m_listening_port;

src/p2p/p2p_protocol_defs.h

@@ -165,7 +165,6 @@ namespace nodetool
   struct basic_node_data
   {
     uuid network_id;                   
-    uint64_t local_time;
     uint32_t my_port;
     uint16_t rpc_port;
     uint32_t rpc_credits_per_hash;
@@ -174,7 +173,6 @@ namespace nodetool
     BEGIN_KV_SERIALIZE_MAP()
       KV_SERIALIZE_VAL_POD_AS_BLOB(network_id)
       KV_SERIALIZE(peer_id)
-      KV_SERIALIZE(local_time)
       KV_SERIALIZE(my_port)
       KV_SERIALIZE_OPT(rpc_port, (uint16_t)(0))
       KV_SERIALIZE_OPT(rpc_credits_per_hash, (uint32_t)0)