Docs: Fix recipe typo (#2156) · gulpjs/gulp@86acdea

Original file line number	Diff line number	Diff line change
`@@ -38,7 +38,7 @@ function getFolders(dir) {`
`38`	`38`
`39`	`39`	`gulp.task('scripts', function(done) {`
`40`	`40`	`var folders = getFolders(scriptsPath);`
`41`		`-if (folder.length === 0) return done(); // nothing to do!`
	`41`	`+if (folders.length === 0) return done(); // nothing to do!`
`42`	`42`	`var tasks = folders.map(function(folder) {`
`43`	`43`	`return gulp.src(path.join(scriptsPath, folder, '/*/.js'))`
`44`	`44`	`// concat into foldername.js`