Fixed bug that caused WebP parameter value 0 to be ignored#52

dreampiggy merged 3 commits intoSDWebImage:masterSDWebImage/SDWebImageWebPCoder:masterfrom

AaaK00:fix_zero_value_in_webp_options_ignoredAaaK00/SDWebImageWebPCoder:fix_zero_value_in_webp_options_ignoredCopy head branch name to clipboard