Allow any value in sensors

app/src/main/java/com/rthoni/camotion/dbo/SensorValueDbo.java

  */
 public class SensorValueDbo extends LuDbo {
 
-    private int _value;
+    private String _value;
 
-    public int getValue() {
+    public String getValue() {
         return _value;
     }
 
-    public void setValue(int value) {
+    public void setValue(String value) {
         _value = value;
     }
 
     @Override
     public void fromJson(JSONObject json) throws JSONException {
-        _value = json.getInt("Value");
+        _value = json.getString("Value");
     }
 
     @Override