Fix the Quick Replies alignement

[janteuni]

I always have arrows for quick replies, and sometimes it's not needed:

• Quick replies should be align at the center of the webchat when they are one or two and don't use all the space.
• When there is multiple quick replies and we need arrows to navigate, the first time they appears on the screen, they are stick to the right and should take all the space of the screen: Like here, when I click a first time to the right arrow, then back to the left arrow, they appears well and take all the space:

[lucasdchamps]

On it ;)

[lucasdchamps]

Looks like the alignment is correct, without having to click on the navigation arrows.