Remove unnecessary type-check; typehints now handle this

lib/SimpleSAML/Auth/ProcessingFilter.php

@@ -50,9 +50,6 @@ abstract class ProcessingFilter
     {
         if (array_key_exists('%priority', $config)) {
             $this->priority = $config['%priority'];
-            if (!is_int($this->priority)) {
-                throw new \Exception('Invalid priority: ' . var_export($this->priority, true));
-            }
             unset($config['%priority']);
         }
     }