Remove redundant no-arg constructor

[Philzen]

Kindly review and advise if this makes sense to merge into 2.15 or whether it should go straight to 2.18 and 3.x

[cowtowncoder]

Yes let's rebase to 2.18 since it really doesn't greatly matter; no more 2.15 versions likely released and for annotations package we try to keep patch versions identical to original .0 (hence not to 2.17).

[cowtowncoder]

@Philzen Thank you for PRs! One process thing that is needed -- unless already done once -- is to get CLA, from:

https://github.com/FasterXML/jackson/blob/master/contributor-agreement.pdf

and the usual way is to print, fill & sign, scan/photo, email to cla at fasterxml dot com.
Only needs to be done before merging the first contribution, good for all current and future contributions.

Thank you -- and once CLA is in, PRs rebased to 2.18, will be happy to merge.

[Philzen]

Closed in favor of #253