Source URL with query string

[teohhanhui]

e.g. https://avatars2.githubusercontent.com/u/548843?v=3&s=96

The query string is not passed on to the source, as the source url is not properly URL-encoded.

Fixing this would introduce a BC break. (We cannot just blindly perform URL decode, as we risk double decoding...) Should the requirement to URL encode be applied to all sources, or should it be configurable per source?