Update routing_controller.dart

[mhbdev]

Solves #1789
This commit will affect AutoTabsRouter path stacking. If the user click on the back button and activeIndex is not homeIndex, then pops to previous active tab not homeIndex.

[mhbdev]

I think I have to consider another condition! Considering that the user has passed through these routes:

homeIndex is 0.

DashBoard -> homeIndex -> 2 -> 1 -> homeIndex -> 3 -> 4

On pop goes from 4 to 3 and then homeIndex and finally pop the whole app.

I have to check if there is no previous route at all, then pop the whole app if the user is on homeIndex.

[Milad-Akarie]

Hey @mhbdev I haven't tested the code yet but from a first a glance I think it might cause a non-ending loop since setActiveRoute sets the previous index.