Test fixups because fallback css now always uses chunked encoding in 1.8.31.3
Test fixups because fallback css now always uses chunked encoding in 1.8.31.3

0x0mar/ngx_pagespeed,wanrui/ngx_pagespeed,digideskio/ngx_pagespeed,wanrui/ngx_pagespeed,digideskio/ngx_pagespeed,0x0mar/ngx_pagespeed