Update the name of the swift branch we check out when
compiling the github lldb swift-4.1-branch sources.
diff --git a/scripts/Xcode/repos/swift-github-swift-4.1-branch.json b/scripts/Xcode/repos/swift-github-swift-4.1-branch.json
index f83574b..cba10f5 100644
--- a/scripts/Xcode/repos/swift-github-swift-4.1-branch.json
+++ b/scripts/Xcode/repos/swift-github-swift-4.1-branch.json
@@ -14,7 +14,7 @@
         {"name": "swift",
          "vcs": "git",
          "url": "https://github.com/apple/swift.git",
-         "ref": "master"},
+         "ref": "swift-4.1-branch"},
 
         {"name": "cmark",
          "vcs": "git",