fix(overmind): fix nested processing of state

Author: christianalfoni

packages/node_modules/overmind/src/utils.ts

@@ -32,7 +32,7 @@ export function processState(state: {}, derivedReferences?: any[]) {
     const value = state[key]
 
     if (isPlainObject(value)) {
-      aggr[key] = this.processState(value)
+      aggr[key] = processState(value, derivedReferences)
     } else if (typeof value === 'function') {
       aggr[key] = new Derived(value)