Do not increment nAttempts by more than one for every Good connection.

This slows the increase of the nAttempts in addrman while partitioned,
 even if the node hasn't yet noticed the partitioning.

src/addrman.cpp

@@ -197,6 +197,9 @@ void CAddrMan::MakeTried(CAddrInfo& info, int nId)
 void CAddrMan::Good_(const CService& addr, int64_t nTime)
 {
     int nId;
+
+    nLastGood = nTime;
+
     CAddrInfo* pinfo = Find(addr, &nId);
 
     // if not found, bail out
@@ -327,7 +330,10 @@ void CAddrMan::Attempt_(const CService& addr, bool fCountFailure, int64_t nTime)
 
     // update info
     info.nLastTry = nTime;
-    if (fCountFailure) info.nAttempts++;
+    if (fCountFailure && info.nLastCountAttempt < nLastGood) {
+        info.nLastCountAttempt = nTime;
+        info.nAttempts++;
+    }
 }
 
 CAddrInfo CAddrMan::Select_(bool newOnly)