fix(overmind): fix issue with devtools error

Author: christianalfoni

packages/node_modules/overmind/src/config/statechart.ts

@@ -474,7 +474,7 @@ export function statechart<C extends IConfiguration, Charts extends Statecharts
 
 
 
-          if (process.env.NODE_ENV === 'development' && currentInstance.devtools) {
+          if (process.env.NODE_ENV === 'development' && currentInstance && currentInstance.devtools) {
             currentInstance.devtools.send({
               type: 'chart',
               data: {