fix: Potential Undefined array key in IsEinfrAssured

Fix the `process` method of `IsEinfrAssured` authproc filter to not spam
logs with undefined key if the attribute is not present in user
attributes.

lib/Auth/Process/IsEinfraAssured.php

@@ -74,9 +74,9 @@ class IsEinfraAssured extends ProcessingFilter
     public function process(&$request)
     {
         $timestamp = 0;
-        if (isset($request['Attributes'][$this->sessionEligibilitiesAttr][$this->eligibilityKey])) {
+        if (!empty($request['Attributes'][$this->sessionEligibilitiesAttr][$this->eligibilityKey])) {
             $timestamp = $request['Attributes'][$this->sessionEligibilitiesAttr][$this->eligibilityKey];
-        } elseif (isset($request['Attributes'][$this->userEligibilitiesAttr][$this->eligibilityKey])) {
+        } elseif (!empty($request['Attributes'][$this->userEligibilitiesAttr][$this->eligibilityKey])) {
             $timestamp = $request['Attributes'][$this->userEligibilitiesAttr][$this->eligibilityKey];
         }