I have a branch
git merge master
First consider not merging integration branches into feature branches.
Second have a look to git rerere command and use it:
$ git config --global rerere.enabled true
git-rerere - Reuse recorded resolution of conflicted merges
In a workflow employing relatively long lived topic branches, the developer sometimes needs to resolve the same conflicts over and over again until the topic branches are done (either merged to the "release" branch, or sent out and accepted upstream)