Bug resolved while editing group names

When you edit group names and saved which you have joined , it throws the error, for "NoReverseMatch" for edit_url, hence on metastudio server "Internal server error" comes for groups which have already edited and saved.
Now bug resolved, modification in url redirections
Modification in : 
```
methods.py  --> check_existing_group() function , made the distinction according to type of parameter passed
node_ajax_view.html  -->  parameters passed in tag "check_group" defined in this template is modified
```