GitLab revert the reverted merge

So you made a mistake and made a revert, then you want to introduce again the code you use in new merge, if you try to make merge request(MR) from branch you made original MR you reverted you will get nothing in that MR. This is not a bug, but a feature of git. Reverting does not roll back, but rather appends the revert to the front of the HEAD. So HEAD now contains both the merge request and the revert, hence why it thinks there is nothing to merge.
So what do we do then is

1. git pull master 
2. get checkout -b new_branch
3. git revert -m 1 37dsd67a48ed2fs1119c184ac7815fc8f3a7967c1

where 3rd line is crucial (find the hash of merge commit), this lines reverts the revert merge we made, "m" option is an mainline parent number, or as it says in docs
Usually you cannot revert a merge because you do not know which side of the merge should be considered the mainline. This option specifies the parent number (starting from 1) of the mainline and allows revert to reverse the change relative to the specified parent.

So with that we should get all the changes we reverted in this new branch, then we can add new changes to this branch and fix if something is needed and finally merge back to master.