another fix

src/preprocess.py

@@ -63,7 +63,7 @@ class DbOp(object):
                         'unit': res[2]
                     }
                 logger.debug(f"{variable=}")
-            return application
+            return variable
         except Exception as e:
             logger.error(f"Error getting variable: {e}")
             raise VariableNotFoundException(appId, converterId, deviceId, variableId)
@@ -104,10 +104,10 @@ def splitTopic(topic):
         deviceId = 'mains',
         variableId = r[0]
     elif (len(r) == 2):
-        (deviceId, variableid) = r
+        (deviceId, variableId) = r
     else:
         raise InvalidTopicException(topic)
-    return (appId, converterId, deviceId, variableid)
+    return (appId, converterId, deviceId, variableId)
     
 def mqttOnConnectCallback(client, userdata, flags, rc):
     logger.info("mqtt connected")
@@ -124,7 +124,7 @@ def mqttOnMessageCallback(client, userdata, message):
         (appId, converterId, deviceId, variableId) = splitTopic(topic)
 
         dbh = DbOp(config)
-        variable = dbh.getVariable(appId, converterId, deviceId, variableid)
+        variable = dbh.getVariable(appId, converterId, deviceId, variableId)
         measurement = {
             "application": variable["application"],
             "variable": variable["variable"],