remove auth details, now provided by env

STS_channels.php

@@ -57,8 +57,8 @@
                 )
 	);
 
-	$username = 'katrin';
-	$password = 'katrin.Pauli%2020';
+    $username = getenv('PHP_ADEI_USERNAME');
+    $password = getenv('PHP_ADEI_PASSWORD');
 	$context = stream_context_create(array(
 		'http' => array(
 			'header'  => "Authorization: Basic " . base64_encode("$username:$password"), "Connection: close\r\n"