Fix case where polyphen2 never rendered when SIFT present

This was caused due to the lazy evaluation logic. Basically, if SIFT was present, then the sift variable was define and evaluated to true. As a result, the lazy or evaluation stopped there an never considered the second statement which assigned the polyphen portion.
Merge pull request #130 from cbmi/issue-110

Fix case where polyphen2 never rendered when SIFT present