check for pending LeaseSet request

Destination.cpp

@@ -464,7 +464,9 @@ namespace client
 		{
 			LeaseSetRequest * request = new LeaseSetRequest (m_Service);
 			request->requestComplete = requestComplete;
-			m_LeaseSetRequests[dest] = request;
+			auto ret = m_LeaseSetRequests.insert (std::pair<i2p::data::IdentHash, LeaseSetRequest *>(dest,request));
+			if (ret.second) // inserted
+			{
 				if (!SendLeaseSetRequest (dest, floodfill, request))
 				{
 					// request failed
@@ -473,6 +475,14 @@ namespace client
 					m_LeaseSetRequests.erase (dest);
 				}
 			}	
+			else // duplicate
+			{
+				LogPrint (eLogError, "Request of ", dest.ToBase64 (), " is pending already");
+				// TODO: queue up requests
+				if (request->requestComplete) request->requestComplete (false);
+				delete request;
+			}	
+		}	
 		else
 			LogPrint (eLogError, "No floodfills found");	
 	}