Catch the TypeError in sensors page

On the sensors page, there is the below error and some sensors are missing:
Uncaught (in promise) TypeError:
Cannot read property 'LowerCaution' of undefined

The root cause is that some sensors do not support all these
Thresholds properties, add the checking to catch such errors.

Tested:
These sensors in redfish/v1/Chassis/$id/Sensors/
can be displayed in sensors web page

Signed-off-by: Yong Li <yong.b.li@linux.intel.com>
Change-Id: Ic80048045ee8e293e693811c246723557489fb35
diff --git a/src/store/modules/Health/SensorsStore.js b/src/store/modules/Health/SensorsStore.js
index 24ad2d1..edcbf7b 100644
--- a/src/store/modules/Health/SensorsStore.js
+++ b/src/store/modules/Health/SensorsStore.js
@@ -53,10 +53,10 @@
               name: data.Name,
               status: data.Status.Health,
               currentValue: data.Reading,
-              lowerCaution: data.Thresholds.LowerCaution.Reading,
-              upperCaution: data.Thresholds.UpperCaution.Reading,
-              lowerCritical: data.Thresholds.LowerCritical.Reading,
-              upperCritical: data.Thresholds.UpperCritical.Reading,
+              lowerCaution: data.Thresholds?.LowerCaution?.Reading,
+              upperCaution: data.Thresholds?.UpperCaution?.Reading,
+              lowerCritical: data.Thresholds?.LowerCritical?.Reading,
+              upperCritical: data.Thresholds?.UpperCritical?.Reading,
               units: data.ReadingUnits
             };
           });