Et2Date: Fix required validation message was always shown after changing a required date

Some missed changes after moving from Lion

api/js/etemplate/Et2Date/Et2Date.ts

@@ -455,7 +455,7 @@ export class Et2Date extends Et2InputWidget(FormControlMixin(ValidateMixin(LitFl
 		};
 	}
 
-	set_value(value)
+	set value(value)
 	{
 		if(!value || value == 0 || value == "0")
 		{
@@ -487,13 +487,8 @@ export class Et2Date extends Et2InputWidget(FormControlMixin(ValidateMixin(LitFl
 		}
 	}
 
-	getValue()
+	get value()
 	{
-		if(this.readonly || this.disabled)
-		{
-			return null;
-		}
-
 		// Copied from flatpickr, since Et2InputWidget overwrote flatpickr.getValue()
 		if(!this._inputElement)
 		{

api/js/etemplate/Validators/Required.ts

@@ -2,6 +2,18 @@ import {Required as LionRequired} from "@lion/form-core";
 
 export class Required extends LionRequired
 {
+	/**
+	 * Returns a Boolean.  True if the test fails
+	 * @param {?} [modelValue]
+	 * @param {?} [param]
+	 * @param {{}} [config]
+	 * @returns {Boolean|Promise<Boolean>}
+	 */
+	execute(modelValue : any, param : any, config : {}) : boolean | Promise<boolean>
+	{
+		return modelValue == "" || modelValue == undefined || modelValue == null;
+	}
+
 	/**
 	 * Give a message about this field being required.  Could be customised according to MessageData.
 	 * @param {MessageData | undefined} data