small corrections to gallery-dl-example.conf

use "'_reddit' in locals()"
instead of ""locals().get('_reddit')"
since the reddit metadata dict could be empty. The latter expression
would evaluate to False in that case, even though it has a reddit parent.

docs/gallery-dl-example.conf

@@ -140,43 +140,43 @@
 
         "reddit":
         {
+            "#": "only spawn child extractors for links to specific sites",
+            "whitelist": ["imgur", "redgifs", "gfycat"],
+
             "#": "put files from child extractors into the reddit directory",
             "parent-directory": true,
 
             "#": "transfer metadata to any child extractor as '_reddit'",
-            "parent-metadata": "_reddit",
-
-            "#": "only spawn child extractors for links to specific sites",
-            "whitelist": ["imgur", "redgifs", "gfycat"]
+            "parent-metadata": "_reddit"
         },
 
         "imgur":
         {
             "#": "use different directory and filename formats when coming from a reddit post",
             "directory":
             {
-                "locals().get('_reddit')": []
+                "'_reddit' in locals()": []
             },
             "filename":
             {
-                "locals().get('_reddit')": "{_reddit[id]} {id}.{extension}",
+                "'_reddit' in locals()": "{_reddit[id]} {id}.{extension}",
                 ""                     : "{id}.{extension}"
             }
         },
 
         "tumblr":
         {
-            "posts": "all",
+            "posts"   : "all",
             "external": false,
-            "reblogs": false,
-            "inline": true,
+            "reblogs" : false,
+            "inline"  : true,
 
             "#": "use special settings when downloading liked posts",
             "likes":
             {
-                "posts": "video,photo,link",
+                "posts"   : "video,photo,link",
                 "external": true,
-                "reblogs": true
+                "reblogs" : true
             }
         },