Fix typo

src/AutoPilotPlugins/PX4/PowerComponent.qml

@@ -110,7 +110,7 @@ QGCView {
                 onCalibrationFailed:    showMessage("ESC Calibration failed", errorMessage, StandardButton.Ok)
                 onCalibrationSuccess:   showMessage("ESC Calibration", "Calibration complete. You can disconnect your battery now if you like.", StandardButton.Ok)
                 onConnectBattery:       showMessage("ESC Calibration", "WARNING: Props must be removed from vehicle prior to performing ESC calibration.\n\nConnect the battery now and calibration will begin.", 0)
-                onDisconnectBattery:    showMessage("ESC Calibration failed", "You must disconnect the battery prior to performing ESC Calibration. Disconnect your battery and try again.", , StandardButton.Ok)
+                onDisconnectBattery:    showMessage("ESC Calibration failed", "You must disconnect the battery prior to performing ESC Calibration. Disconnect your battery and try again.", StandardButton.Ok)
             }
 
             Column {