[p2p] Remove dead code

The else clause is dead code because the only way to not enter the if branch is
if TX_WITNESS_STRIPPED is true. In that case, it would not have a witness to
match the `tx.HasWitness()` else condition.

Co-authored-by: Adam Jonas <jonas@chaincode.com>
Co-authored-by: John Newbery <john@johnnewbery.com>

src/net_processing.cpp

@@ -3121,8 +3121,6 @@ void PeerLogicValidation::ProcessMessage(CNode& pfrom, const std::string& msg_ty
                 if (RecursiveDynamicUsage(*ptx) < 100000) {
                     AddToCompactExtraTransactions(ptx);
                 }
-            } else if (tx.HasWitness() && RecursiveDynamicUsage(*ptx) < 100000) {
-                AddToCompactExtraTransactions(ptx);
             }
 
             if (pfrom.HasPermission(PF_FORCERELAY)) {