cling travis: remove stray "--overwrite".
cling travis: remove stray "--overwrite".

karies/cling,root-mirror/cling,root-mirror/cling,karies/cling,karies/cling,root-mirror/cling,karies/cling,root-mirror/cling,root-mirror/cling,root-mirror/cling,karies/cling,karies/cling