Allow all https images from anywhere, fixes #941, closes #942

app/config/config_prod.yml

@@ -94,13 +94,7 @@ nelmio_security:
                 - '*.algolianet.com'
             img-src:
                 - 'self'
-                - 'https://www.gravatar.com/'
-                - 'https://*.githubusercontent.com'
-                - 'https://raw.github.com/'
-                - 'https://rawcdn.githack.com/'
-                - 'https://github.com/'
-                - 'https://gitlab.com/'
-                - 'https://www.google-analytics.com/'
+                - 'https:'
                 - 'http://www.google-analytics.com/'
             style-src:
                 - 'self'