Remove old FT versions to prevent rebuilding them

library/nuxeo

@@ -4,13 +4,11 @@ latest: git://github.com/nuxeo/docker-nuxeo@c8f5d5bd4fedda1ee72eb29eac5fbb0b0a49
 FT: git://github.com/nuxeo/docker-nuxeo@c8f5d5bd4fedda1ee72eb29eac5fbb0b0a490155 8.2
 8: git://github.com/nuxeo/docker-nuxeo@c8f5d5bd4fedda1ee72eb29eac5fbb0b0a490155 8.2
 8.2: git://github.com/nuxeo/docker-nuxeo@c8f5d5bd4fedda1ee72eb29eac5fbb0b0a490155 8.2
-8.1: git://github.com/nuxeo/docker-nuxeo@09c50e490336f28caf1278c6bffaa02e79c0f4b4 8.1
 
 LTS-2015: git://github.com/nuxeo/docker-nuxeo@09c50e490336f28caf1278c6bffaa02e79c0f4b4 7.10
 LTS: git://github.com/nuxeo/docker-nuxeo@09c50e490336f28caf1278c6bffaa02e79c0f4b4 7.10
 7.10: git://github.com/nuxeo/docker-nuxeo@09c50e490336f28caf1278c6bffaa02e79c0f4b4 7.10
 7: git://github.com/nuxeo/docker-nuxeo@09c50e490336f28caf1278c6bffaa02e79c0f4b4 7.10
-7.4: git://github.com/nuxeo/docker-nuxeo@09c50e490336f28caf1278c6bffaa02e79c0f4b4 7.4
 
 LTS-2014: git://github.com/nuxeo/docker-nuxeo@09c50e490336f28caf1278c6bffaa02e79c0f4b4 6.0
 6: git://github.com/nuxeo/docker-nuxeo@09c50e490336f28caf1278c6bffaa02e79c0f4b4 6.0