hugolib: Defer the unlock in orderedMap.Add
hugolib: Defer the unlock in orderedMap.Add

Just in case someone tries to recover from the potential panic.

fedelibre/hugo,fedelibre/hugo,fedelibre/hugo,gohugoio/hugo,anthonyfok/hugo,mdhender/hugo,anthonyfok/hugo,gohugoio/hugo,mdhender/hugo,fedelibre/hugo,anthonyfok/hugo,gohugoio/hugo,mdhender/hugo,mdhender/hugo