don't delete unreachable routers if too few

libi2pd/NetDb.cpp

@@ -560,6 +560,9 @@ namespace data
 				updatedCount++;
 				continue;
 			}
+			// make router reachable back if too few routers
+			if (it.second->IsUnreachable () && total - deletedCount < NETDB_MIN_ROUTERS)	
+				it.second->SetUnreachable (false); 
 			// find & mark expired routers
 			if (it.second->UsesIntroducer ())
 			{