fix(gatsby-dev-cli): move package.json file check after pathToRepo ha…

…ndling (#11565)

packages/gatsby-dev-cli/src/index.js

@@ -36,12 +36,6 @@ You typically only need to configure this once.`
 const conf = new Configstore(pkg.name)
 
 const fs = require(`fs-extra`)
-const havePackageJsonFile = fs.existsSync(`package.json`)
-
-if (!havePackageJsonFile) {
-  console.error(`Current folder must have a package.json file!`)
-  process.exit()
-}
 
 let pathToRepo = argv.setPathToRepo
 
@@ -53,6 +47,13 @@ if (pathToRepo) {
   process.exit()
 }
 
+const havePackageJsonFile = fs.existsSync(`package.json`)
+
+if (!havePackageJsonFile) {
+  console.error(`Current folder must have a package.json file!`)
+  process.exit()
+}
+
 const gatsbyLocation = conf.get(`gatsby-location`)
 
 if (!gatsbyLocation) {