Remove false assertion

As of 4df7b540a2263b87577a8805b3ca08e5e3e4da65, the assertion no
longer holds.

src/DefaultPeerStorage.cc

@@ -67,7 +67,6 @@ DefaultPeerStorage::DefaultPeerStorage()
 
 DefaultPeerStorage::~DefaultPeerStorage()
 {
-  assert(uniqPeers_.size() == unusedPeers_.size() + usedPeers_.size());
 }
 
 size_t DefaultPeerStorage::countAllPeer() const