Update rust.json

Author: oli-obk

highfive/configs/rust-lang/rust.json

@@ -102,7 +102,7 @@
         "src/tools/rustfmt": {
             "message": "Some changes occurred in src/tools/rustfmt.",
             "reviewers": ["@calebcartwright"]
-        }
+        },
         "src/tools/clippy": {
             "message": "Some changes occurred in src/tools/clippy.",
             "reviewers": ["@rust-lang/clippy"]