Update test to show that it doesn't capture the fake dune anymore

Signed-off-by: Marek Kubica <[email protected]>

Author: Leonidas-from-XIV

test/blackbox-tests/test-cases/pkg/different-dune-in-path.t

@@ -91,7 +91,6 @@ Call Dune with an absolute PATH as argv[0]:
   $ PATH=$fakepath $DUNE build "$pkg_root/$foo_digest/target/"
   Fake dune! (args: build -p foo @install)
   $ PATH=$fakepath $DUNE build "$pkg_root/$bar_digest/target/"
-  Fake dune! (args: build -p bar @install)
 
 Make sure that fake dune is not picked up when dune is called with argv[0] = "dune":