Merge branch 'cm_1083654_create-serialletter' into '2021.1.1'

[Projekt: xRM-ContactManagement][TicketNr.: 1083654][Serienbrief: Fehlermeldung bei Neuanlage]

See merge request xrm/basic!1115

entity/SerialLetter_entity/entityfields/date_new/valueProcess.js

 import("system.result");
 import("system.vars");
 
-if (vars.get("$tis.value") != null)
+if (vars.get("$this.value") != null)
 {
     result.string(vars.get("$sys.date"));    
 }
\ No newline at end of file