Handle wash_out changed XML format

I believe this commit (not yet in current stable gem) has altered the expected XML that qbwc should pass to it: https://github.com/inossidabile/wash_out/commit/24a77f4a3d874562732c6e8c3a30e8defafea7cb. AFAICT this is a breaking change when qbwc uses edge wash_out. 

I'd appreciate another set of eyes on this.