Update devcontainer.json (#4427)

Author: jody89

.devcontainer/devcontainer.json

@@ -9,7 +9,7 @@
     "settings": {
         "terminal.integrated.shell.linux": "/bin/bash"
     },
-    "extensions": [
+    "extensions": [true][
         "ms-vscode.cpptools"
     ]
-}
+}