fix - migration 30 undefinds (#6079)

app/scripts/migrations/030.js

@@ -24,7 +24,7 @@ module.exports = {
 
 function transformState (state) {
   const newState = state
-
+  if (state.PreferencesController) {
     const frequentRpcListDetail = newState.PreferencesController.frequentRpcListDetail
     if (frequentRpcListDetail) {
       frequentRpcListDetail.forEach((rpc, index) => {
@@ -34,7 +34,8 @@ function transformState (state) {
       })
       newState.PreferencesController.frequentRpcListDetail = frequentRpcListDetail
     }
-
+  }
+  if (state.NetworkController) {
     if (newState.NetworkController.network && Number.isNaN(parseInt(newState.NetworkController.network))) {
       delete newState.NetworkController.network
     }
@@ -42,6 +43,7 @@ function transformState (state) {
     if (newState.NetworkController.provider && newState.NetworkController.provider.chainId && Number.isNaN(parseInt(newState.NetworkController.provider.chainId))) {
       delete newState.NetworkController.provider.chainId
     }
+  }
 
   return newState
 }