core/webauthn: set webauthn interface in its app not in main.py

This way the other messages (WebAuthnListResidentCredentials etc.) get
registered in device debug build and can be tested.

Updates #591

core/src/apps/webauthn/__init__.py

@@ -1,10 +1,10 @@
-from trezor import io, loop, wire
+from trezor import loop, utils, wire
 from trezor.messages import MessageType
 
 from apps.webauthn.fido2 import handle_reports
 
 
-def boot(iface: io.HID) -> None:
+def boot() -> None:
     wire.add(
         MessageType.WebAuthnListResidentCredentials,
         __name__,
@@ -18,4 +18,7 @@ def boot(iface: io.HID) -> None:
         __name__,
         "remove_resident_credential",
     )
-    loop.schedule(handle_reports(iface))
+    if not __debug__ or utils.EMULATOR:
+        import usb
+
+        loop.schedule(handle_reports(usb.iface_webauthn))

core/src/main.py

@@ -50,8 +50,7 @@ def _boot_default() -> None:
     if __debug__:
         import apps.debug
     if not utils.BITCOIN_ONLY:
-        if not __debug__ or utils.EMULATOR:
-            import apps.webauthn
+        import apps.webauthn
 
     # boot applications
     apps.homescreen.boot()
@@ -71,8 +70,7 @@ def _boot_default() -> None:
     if __debug__:
         apps.debug.boot()
     if not utils.BITCOIN_ONLY:
-        if not __debug__ or utils.EMULATOR:
-            apps.webauthn.boot(usb.iface_webauthn)
+        apps.webauthn.boot()
 
     # run main event loop and specify which screen is the default
     from apps.homescreen.homescreen import homescreen