Manifest has incorrect implementation version

[sschr15]

In a freshly built all-jar using the included gradle wrapper and on the latest commit as of creating this issue (f73eb92), the generated manifest has a questionable value that appears Gradle has not correctly given. Below is the generated manifest:

Manifest-Version: 1.0
Implementation-Title: Patchwork Patcher
Implementation-Version: task ':jar' property 'archiveVersion'
Main-Class: net.patchworkmc.patcher.ui.PatchworkUI

This apparent problem is in all three shadow jars, but it is not present in the jar not containing dependencies.