Custom Pages Initial zaproxy#6

clearFields() should include discardAllEdits() on text field.

src/org/zaproxy/zap/extension/custompages/DialogAddCustomPage.java

@@ -141,6 +141,7 @@ protected void performAction() {
 	@Override
 	protected void clearFields() {
 		this.contentTextField.setText("");
+		this.contentTextField.discardAllEdits();
 		this.enabledCheckBox.setSelected(true);
 		this.regexCheckBox.setSelected(false);
 		this.newCustomPageTypesCombo.setSelectedIndex(0);