configure: hide ocamlfind message when a dependency is missing
configure: hide ocamlfind message when a dependency is missing

neojski/merlin,chriskonstad/merlin,rgrinberg/merlin,dra27/merlin,rgrinberg/merlin,ocaml/merlin,haselwarter/merlin,haselwarter/merlin,the-lambda-church/merlin,chambart/merlin,fxfactorial/merlin,dra27/merlin,fxfactorial/merlin,neojski/merlin,chambart/merlin,fxfactorial/merlin,ocaml/merlin,neojski/merlin,chriskonstad/merlin,neojski/merlin,haselwarter/merlin,ocaml/merlin,rgrinberg/merlin,fxfactorial/merlin,ocaml/merlin,chambart/merlin,haselwarter/merlin,rgrinberg/merlin,dra27/merlin,the-lambda-church/merlin,the-lambda-church/merlin,dra27/merlin,chambart/merlin