Bandit 1.10.1 does not support read_timeout/write_timeout in http_1_options
or stream_idle_timeout in http_2_options. These invalid options caused the
application to crash on startup with 'Unsupported key(s) in http_1_options'.
Moved read_timeout to thousand_island_options where it belongs, and removed
the unsupported write_timeout and stream_idle_timeout options.
Also fixed UserSettingsHTMLTest to include the missing mobile_sessions assign
that is required by the edit.html.heex template.
