[PHP8.1] Contact data deprecated errors (#38101)

* Ensure webpage is set when creating contacts before validating

* Fix parsing empty contact properties

administrator/components/com_contact/src/Table/ContactTable.php

@@ -110,10 +110,16 @@ public function store($updateNulls = true)
 		}
 
 		// Store utf8 email as punycode
-		$this->email_to = PunycodeHelper::emailToPunycode($this->email_to);
+		if ($this->email_to !== null)
+		{
+			$this->email_to = PunycodeHelper::emailToPunycode($this->email_to);
+		}
 
 		// Convert IDN urls to punycode
-		$this->webpage = PunycodeHelper::urlToPunycode($this->webpage);
+		if ($this->webpage !== null)
+		{
+			$this->webpage = PunycodeHelper::urlToPunycode($this->webpage);
+		}
 
 		// Verify that the alias is unique
 		$table = Table::getInstance('ContactTable', __NAMESPACE__ . '\\', array('dbo' => $this->getDbo()));
@@ -151,7 +157,7 @@ public function check()
 
 		$this->default_con = (int) $this->default_con;
 
-		if (InputFilter::checkAttribute(array('href', $this->webpage)))
+		if ($this->webpage !== null && InputFilter::checkAttribute(array('href', $this->webpage)))
 		{
 			$this->setError(Text::_('COM_CONTACT_WARNING_PROVIDE_VALID_URL'));