fix wallhaven.cc imageByFragment regexp

Author: spaceyuck

scrapers/Wallhaven.yml

@@ -10,7 +10,7 @@ imageByFragment:
     filename:
       - regex: "[^a-zA-Z\\d\\-._~ ]" # clean filename so that it can construct a valid url
         with: ""
-      - regex: "^.*[ _.\\-]([a-z\\d]{6}).[a-zA-Z\\d]{3,}$" # try to extract ID postfix
+      - regex: "^.*[ _.\\-]([a-z\\d]{6})\\.[a-zA-Z\\d]{3,}$" # try to extract ID postfix
         with: "https://wallhaven.cc/api/v1/w/$1"
   scraper: imageScraper