[netprocessing] disconnect node that sends filterclear

-nodes not serving bloomfilters should disconnect peers
that send filterclear, just like filteradd and filterload
-nodes that want to enable/disable txrelay should use
feefilter

src/net_processing.cpp

@@ -3490,13 +3490,15 @@ bool ProcessMessage(CNode& pfrom, const std::string& msg_type, CDataStream& vRec
     }
 
     if (msg_type == NetMsgType::FILTERCLEAR) {
+        if (!(pfrom.GetLocalServices() & NODE_BLOOM)) {
+            pfrom.fDisconnect = true;
+            return true;
+        }
         if (pfrom.m_tx_relay == nullptr) {
             return true;
         }
         LOCK(pfrom.m_tx_relay->cs_filter);
-        if (pfrom.GetLocalServices() & NODE_BLOOM) {
-            pfrom.m_tx_relay->pfilter = nullptr;
-        }
+        pfrom.m_tx_relay->pfilter = nullptr;
         pfrom.m_tx_relay->fRelayTxes = true;
         return true;
     }