Respect the new values in com_menus Module Assignment

#### Corrects one of the two problems in com_menus #5304

#### The problem
Changes on the title and the position of any module in com_menus never actually reflected in the relative view.

#### Tests Instructions
First observe the problem:
Go to administrator-> Menus -> Select a menu
Select a menu item e.g. Home and go to edit screen
Go to Module Assignment (last tab) and click on any of the available modules
On the modal change either the position or the title (or both)
save and close the modal
Observe that title and position DOESN’T reflect on the changes you’ve made.

Apply this PR and repeat the same procedure. Observe the title and position.
Everything should work fine now

#### Preview:
![screen shot 2014-12-04 at 6 33 53](https://cloud.githubusercontent.com/assets/3889375/5301805/64361b90-7be4-11e4-9e3e-bcc481a40518.png)