examples/get_profiles should be updated to use account().fetch_user_profile

[Half-Shot]

If only because it would save the next person a hour researching into the 401 errors when using Synapse with reasonably hardened configs, ultimately caused by matrix-org/matrix-spec#2254 and ruma/ruma#380.

[zecakeh]

It seems like the purpose of this example was to demonstrate how to make an arbitrary request with Client::send(): 7201749. Maybe the example should be changed to make a request to a different endpoint instead?