fix command

Author: OmarAyo

docs/Manual/Security/Starter/README.md

@@ -19,8 +19,8 @@ _--javascript.execute-string_ option of the _arangosh_ binary, e.g.:
 
 ```bash
 arangosh --server.endpoint your-server-endpoint \
-    --server.password ""
-    --javascript.execute-string 'require("org/arangodb/users").update("root", "mypwd");
+    --server.password "" \
+    --javascript.execute-string 'require("org/arangodb/users").update("root", "mypwd");'
 ```
 
 where "mypwd" is the new password you want to set.