hwmon-temp-sensor: Support sensor with missing labels

Currently the hwmon temp sensors forces all sensor labels to be
required even when we don't want to expose all of them.

For example,
```
        {
            "Address": "0x4e",
            "Bus": "$bus",
            "Name": "test0",
            "Name1": "test1",
            "Name2": "test2",
            "Name3": "test3",
            "Labels": ["temp4"],
            "Type": "MAX31730"
        },
```

It will have
```
$ /tmp/hwmontempsensor &
error getting  SpecialMode status No route to host
malloc(): unsorted double linked list corrupted
-sh: line 438: 20466 Aborted                 (core dumped)
    /tmp/hwmontempsensor
```

It needs the `Labels` to be `["temp1, "temp2", "temp3", "temp4"]` to
work properly.

With the fix to the daemon it doesn't need it anymore and we can expose
only the sensor that we want.

Tested:
Working and didn't crash
```
busctl tree xyz.openbmc_project.HwmonTempSensor
`-/xyz
  `-/xyz/openbmc_project
    `-/xyz/openbmc_project/sensors
      `-/xyz/openbmc_project/sensors/temperature
        `-/xyz/openbmc_project/sensors/temperature/test3
```

Change-Id: I73d236cf36f22ec0e64a1603b83b14e29e56d36b
Signed-off-by: Willy Tu <wltu@google.com>
diff --git a/src/HwmonTempMain.cpp b/src/HwmonTempMain.cpp
index e5671b1..388a7a4 100644
--- a/src/HwmonTempMain.cpp
+++ b/src/HwmonTempMain.cpp
@@ -477,10 +477,7 @@
                                         hwmonName.end());
                     }
                 }
-                if (hwmonName.empty())
-                {
-                    configMap.erase(findSensorCfg);
-                }
+                configMap.erase(findSensorCfg);
             }
         });
     getter->getConfiguration(