Don't swallow random exceptions

Catching any exception here will not display an error if e.g. entitiy
conversion fails.

toot/auth.py

@@ -8,7 +8,7 @@ def find_instance(base_url: str) -> Instance:
     try:
         instance = api.get_instance(base_url).json()
         return from_dict(Instance, instance)
-    except Exception:
+    except ApiError:
         raise ConsoleError(f"Instance not found at {base_url}")