Fix const.

controller/RethinkDB.cpp

@@ -253,7 +253,7 @@ RethinkDB::~RethinkDB()
 	_heartbeatThread.join();
 }
 
-void RethinkDB::waitForReady() const
+void RethinkDB::waitForReady()
 {
 	while (_ready > 0) {
 		if (!_waitNoticePrinted) {

controller/RethinkDB.hpp

@@ -34,7 +34,7 @@ public:
 	RethinkDB(EmbeddedNetworkController *const nc,const Address &myAddress,const char *path);
 	virtual ~RethinkDB();
 
-	virtual void waitForReady() const;
+	virtual void waitForReady();
 
 	virtual void save(const nlohmann::json &record);