SMB/UPnP browsing regression

Description

!2047 (merged) attempted to fix a crash where 2 upnp MediaDiscoverers were launched at the same time which crashes in libvlc. It was not really successful as :

it still crashes sometimes (if the remote access is activated and the user open the file browser)
it caused a regression making the SMB/upnp shares hard to navigate (they have to wait the sub-directory parsing end to be bale to navigate further)

More info and a proposal will be added to the comments.

Context

App version

Android version

Device model

App mode

Smartphone

Auto