Minor improvements

1) gen_otp supports single use OTP secrets
2) improve database config check logic
3) reconnect websocket routine to engine (apart from the exchange pair syncer)
4) ImPrOvE CoNsIsTeNcY wItH LoG OuTpUt

engine/routines.go

@@ -295,11 +295,21 @@ func WebsocketRoutine() {
 						common.IsEnabled(Bot.Exchanges[i].IsWebsocketEnabled()))
 				}
 
+				// TO-DO: expose IsConnected() and IsConnecting so this can be simplified
 				if Bot.Exchanges[i].IsWebsocketEnabled() {
 					ws, err := Bot.Exchanges[i].GetWebsocket()
 					if err != nil {
+						log.Errorf(log.WebsocketMgr, "Exchange %s GetWebsocket error: %s\n",
+							Bot.Exchanges[i].GetName(), err)
 						return
 					}
+
+					// Exchange sync manager might have already started ws
+					// service or is in the process of connecting, so check
+					if ws.IsConnected() || ws.IsConnecting() {
+						return
+					}
+
 					// Data handler routine
 					go WebsocketDataHandler(ws)