protocol: drop peers we can't download anything from in sync mode

instead of the (incorrect) check for whether we think we might have
a user for it at some point in the near future. We can reconnect.

src/cryptonote_protocol/cryptonote_protocol_handler.inl

@@ -2298,30 +2298,16 @@ skip:
         return true;
       }
 
-      // if we're still around, we might be at a point where the peer is pruned, so we could either
-      // drop it to make space for other peers, or ask for a span further down the line
-      const uint32_t next_stripe = get_next_needed_pruning_stripe().first;
-      const uint32_t peer_stripe = tools::get_pruning_stripe(context.m_pruning_seed);
-      const uint32_t local_stripe = tools::get_pruning_stripe(m_core.get_blockchain_pruning_seed());
-      if (!(m_sync_pruned_blocks && peer_stripe == local_stripe) && next_stripe && peer_stripe && next_stripe != peer_stripe)
+      // we can do nothing, so drop this peer to make room for others unless we think we've downloaded all we need
+      const uint64_t blockchain_height = m_core.get_current_blockchain_height();
+      if (std::max(blockchain_height, m_block_queue.get_next_needed_height(blockchain_height)) >= m_core.get_target_blockchain_height())
       {
-        // at this point, we have to either close the connection, or start getting blocks past the
-        // current point, or become dormant
-        MDEBUG(context << "this peer is pruned at seed " << epee::string_tools::to_string_hex(context.m_pruning_seed) <<
-            ", next stripe needed is " << next_stripe);
-        if (!context.m_is_income)
-        {
-          if (should_drop_connection(context, next_stripe))
-          {
-            m_p2p->add_used_stripe_peer(context);
-            return false; // drop outgoing connections
-          }
-        }
-        // we'll get back stuck waiting for the go ahead
         context.m_state = cryptonote_connection_context::state_normal;
         MLOG_PEER_STATE("Nothing to do for now, switching to normal state");
         return true;
       }
+      MLOG_PEER_STATE("We can download nothing from this peer, dropping");
+      return false;
     }
 
 skip: