fix typo from bad merge (#744)

diff --git a/helm/openwhisk/runtimes.json b/helm/openwhisk/runtimes.json
index 58acca4..2a20d4e 100644
--- a/helm/openwhisk/runtimes.json
+++ b/helm/openwhisk/runtimes.json
@@ -41,7 +41,7 @@
                     "attachmentName": "codefile",
                     "attachmentType": "text/plain"
                 }
-            },
+            }
         ],
         "python": [
             {