Fix refs to be correct, instead of to Sam's branch

I failed to do this when merging. Mea culpa.

1 files changed, 1 insertions, 1 deletions

diff --git a/core.morph b/core.morph
index 8c79f281..f375f5b3 100644
--- a/core.morph
+++ b/core.morph
@@ -5,7 +5,7 @@
     "build-depends": [
         {
             "repo": "baserock:baserock/morphs",
-            "ref": "baserock/samthursfield/build-essential",
+            "ref": "master",
             "morph": "build-essential"
         }
     ],