修复蓝牙扫描界面不自动扫描的bug

lib/pages/mh_page/device/controller/mht_bluetooth_controller.dart

@@ -189,6 +189,7 @@ class MHTBlueToothController extends GetControllerEx<MHTBlueToothModel> {
         return res;
       } else {
         model.deviceDataStatus = [];
+        return ApiResponse(code:1, msg: "".tr);
       }
     } catch (e) {
       print("获取设备状态异常: $e");

lib/pages/mh_page/device/mht_blueteeth_device_page.dart

@@ -112,6 +112,7 @@ class _MHTBlueteethDevicePageState extends State<MHTBlueteethDevicePage> {
   }
 
   void _startScanning() async {
+    try {
       if (!mounted || isScanning || !mhtBlueToothController.shouldScan.value)
         return;
 
@@ -204,6 +205,13 @@ class _MHTBlueteethDevicePageState extends State<MHTBlueteethDevicePage> {
           });
         }
       }
+    } catch (e) {
+      ef.log("$e");
+    } finally {
+      setState(() {
+        isScanning = false;         
+      });
+    }
   }
 
   void _startPeriodicScan() {