Fixed a bug in how %replace is handled when 'target' is specified to avoid...

Fixed a bug in how %replace is handled when 'target' is specified to avoid multiple attribute values
instead of replacing the attribute value.

modules/core/lib/Auth/Process/AttributeAlter.php

@@ -152,7 +152,7 @@ class sspmod_core_Auth_Process_AttributeAlter extends SimpleSAML_Auth_Processing
                     if ($this->subject === $this->target) {
                         $value = $new_value;
                     } else {
-                        $attributes[$this->target][] = $new_value;
+                        $attributes[$this->target] = array($new_value);
                     }
                 }
             }