Fix PHP keys

Author: abnegate

templates/php/src/Enums/Enum.php.twig

@@ -6,7 +6,8 @@ use JsonSerializable;
 
 class {{ enum.name | caseUcfirst | overrideIdentifier }} implements JsonSerializable
 {
-    {%~ for key in enum.enum %}
+    {%~ for value in enum.enum %}
+    {%~ set key = enum.keys is empty ? value : enum.keys[loop.index0] %}
     private static {{ enum.name | caseUcfirst }} ${{ key | caseEnumKey }};
     {%~ endfor %}