fix(api.js): rename parameter 'optionalPromiseConstructor'
fix(api.js): rename parameter 'optionalPromiseConstructor'

This was previously renamed due to no longer being the first parameter, but this line was never
changed. Tests reveal that this is a problem.

nylas/inbox.js,nylas/inbox.js,iconartus/inbox.js,MobileWorks/inbox.js,MobileWorks/inbox.js,iconartus/inbox.js,iconartus/inbox.js,MobileWorks/inbox.js