Merge pull request astaxie#929 from invzhi/master

Fix typo: banane -> banana

Author: astaxie

zh/04.2.md

@@ -88,13 +88,13 @@ if m, _ := regexp.MatchString(`^(1[3|4|5|8][0-9]\d{4,8})$`, r.Form.Get("mobile")
 <select name="fruit">
 <option value="apple">apple</option>
 <option value="pear">pear</option>
-<option value="banane">banane</option>
+<option value="banana">banana</option>
 </select>
 ```
 那么我们可以这样来验证
 ```Go
 
-slice:=[]string{"apple","pear","banane"}
+slice:=[]string{"apple","pear","banana"}
 
 v := r.Form.Get("fruit")
 for _, item := range slice {