travis: add missing -L
travis: add missing -L

mroonga/mroonga,yoku0825/mroonga,yoku0825/mroonga,mroonga/mroonga,mroonga/mroonga,yoku0825/mroonga,yoku0825/mroonga,yoku0825/mroonga,yoku0825/mroonga,mroonga/mroonga