Remove --skip-project-specific flag

Summary: This doesn't do anything anymore and is going to be removed in D23993306, let's remove it here first.

Reviewed By: yns88

Differential Revision: D23993954

fbshipit-source-id: 4d7dd5f992e34be7a0da16ce7cf59810407649c4

build/fbcode_builder/getdeps/fetcher.py

@@ -599,7 +599,6 @@ class ShipitTransformerFetcher(Fetcher):
                     "--skip-source-clean",
                     "--skip-push",
                     "--skip-reset",
-                    "--skip-project-specific",
                     "--destination-use-anonymous-https",
                     "--create-new-repo-output-path=" + tmp_path,
                 ]