MAX: format desiredTemperature with fixed precision

This make the new longpoll update of dropdowns work.

git-svn-id: https://fhem.svn.sourceforge.net/svnroot/fhem/trunk/fhem@2200 2b470e98-0d58-463d-a4d8-8e2adae1ed80

FHEM/10_MAX.pm

@@ -264,7 +264,8 @@ MAX_Parse($$)
 
     readingsBeginUpdate($shash);
     readingsBulkUpdate($shash, "battery", $batterylow ? "low" : "ok");
-    readingsBulkUpdate($shash, "desiredTemperature", $temperaturesetpoint);
+    #This formatting must match with in MAX_Set:$templist
+    readingsBulkUpdate($shash, "desiredTemperature", sprintf("%2.1f",$temperaturesetpoint));
     readingsBulkUpdate($shash, "valveposition", $valveposition);
     if($measuredTemperature ne "") {
       readingsBulkUpdate($shash, "temperature", $measuredTemperature);