F-Droid can't build

``` Submodule 'lemuroid-cores' (https://github.com/Swordfish90/LemuroidCores) registered for path 'lemuroid-cores' Cloning into '/home/vagrant/build/com.swordfish.lemuroid/lemuroid-cores'... fatal: remote error: upload-pack: not our ref fee2e824525daa22bcf318f96127fe43fa8a15ad fatal: Fetched in submodule path 'lemuroid-cores', but it did not contain fee2e824525daa22bcf318f96127fe43fa8a15ad. Direct fetching of that commit failed. ```