Reset privet destination loading when destination store is reset
Resetting destination store will clear all destinations.
If hasLoadedAllPrivetDestinations is not reset, privet destination
list will not get repopulated after reset_ (provided that the privet
destination loading had previously finished)
BUG=None
TEST=
On network with some privet printers setup:
1. Open print preview (Ctrl+P) and try to change selected destination
2. There should be some privet printers listed under "Local destinations"
3. When local destination loading is done (the spinner disappears)
add another account
4. Make sure "Local Destinations" list gets repopulated with
privet printers
Review URL: https://codereview.chromium.org/
871853003
Cr-Commit-Position: refs/heads/master@{#314176}