Use unique_ptr for pfilter (CBloomFilter)

src/net.h

@@ -648,7 +648,7 @@ public:
     bool fSentAddr;
     CSemaphoreGrant grantOutbound;
     CCriticalSection cs_filter;
-    CBloomFilter* pfilter;
+    std::unique_ptr<CBloomFilter> pfilter;
     std::atomic<int> nRefCount;
 
     const uint64_t nKeyedNetGroup;