Exception if unmerged files exists

[tristanlins]

fatal: git-write-tree: error building trees
Kann den aktuellen Zustand des Index nicht speichern
io.bit3.mgpm.worker.GitProcessException: execution of "git stash save --include-untracked --all Stash before mgpm update" in "/home/..." failed with exit code 1: pom.xml: unmerged (...)