[net processing] Simplify sendcmpct processing

nCMPCTBLOCKVersion must always be 2 when processing.

Author: jnewbery

src/net_processing.cpp

@@ -2891,17 +2891,15 @@ void PeerManagerImpl::ProcessMessage(CNode& pfrom, const std::string& msg_type,
         // fProvidesHeaderAndIDs is used to "lock in" version of compact blocks we send (fWantsCmpctWitness)
         if (!State(pfrom.GetId())->fProvidesHeaderAndIDs) {
             State(pfrom.GetId())->fProvidesHeaderAndIDs = true;
-            State(pfrom.GetId())->fWantsCmpctWitness = nCMPCTBLOCKVersion == 2;
+            State(pfrom.GetId())->fWantsCmpctWitness = true;
         }
-        if (State(pfrom.GetId())->fWantsCmpctWitness == (nCMPCTBLOCKVersion == 2)) { // ignore later version announces
+        if (State(pfrom.GetId())->fWantsCmpctWitness) {
             State(pfrom.GetId())->fPreferHeaderAndIDs = fAnnounceUsingCMPCTBLOCK;
             // save whether peer selects us as BIP152 high-bandwidth peer
             // (receiving sendcmpct(1) signals high-bandwidth, sendcmpct(0) low-bandwidth)
             pfrom.m_bip152_highbandwidth_from = fAnnounceUsingCMPCTBLOCK;
         }
-        if (!State(pfrom.GetId())->fSupportsDesiredCmpctVersion) {
-            State(pfrom.GetId())->fSupportsDesiredCmpctVersion = (nCMPCTBLOCKVersion == 2);
-        }
+        State(pfrom.GetId())->fSupportsDesiredCmpctVersion = true;
         return;
     }