fix(nav): change zh to en in en page navbar.
diff --git a/_jade/en/nav-mixin.jade b/_jade/en/nav-mixin.jade
index 06c6ee3..de923a8 100644
--- a/_jade/en/nav-mixin.jade
+++ b/_jade/en/nav-mixin.jade
@@ -31,7 +31,7 @@
li
a(href='#{hostParam}/en/faq.html') FAQ
li
- a(href='#{hostParam}/zh/tutorial.html#ECharts%205%20Upgrade%20Guide') V5 Upgrade Guide
+ a(href='#{hostParam}/en/tutorial.html#ECharts%205%20Upgrade%20Guide') V5 Upgrade Guide
span.new new
li#nav-download.dropdown
a(href='#', class="dropdown-toggle", data-toggle="dropdown") Download