LiveView handler detatched due to URI parse error

[tomtaylor]

Describe the bug

We've just upgraded from 1.29.x to 1.33.0. We're seeing an issue where the LiveView handler is detaching due to a URI parse error:

Handler {:new_relic, :phoenix_live_view} has failed and has been detached. Class=:error
Reason=:function_clause
Stacktrace=[
  {URI, :parse, [nil], [file: ~c"lib/uri.ex", line: 783]},
  {NewRelic.Telemetry.PhoenixLiveView, :handle_event, 4,
   [file: ~c"lib/new_relic/telemetry/phoenix_live_view.ex", line: 81]},
  {:telemetry, :"-execute/3-fun-0-", 4,
   [file: ~c"/tmp/build_54168d73/deps/telemetry/src/telemetry.erl", line: 167]},
  {:lists, :foreach_1, 2, [file: ~c"lists.erl", line: 2310]},
  {:telemetry, :span, 3,
   [file: ~c"/tmp/build_54168d73/deps/telemetry/src/telemetry.erl", line: 318]},
  {Phoenix.LiveView.Channel, :verified_mount, 8,
   [file: ~c"lib/phoenix_live_view/channel.ex", line: 1177]},
  {Phoenix.LiveView.Channel, :handle_info, 2,
   [file: ~c"lib/phoenix_live_view/channel.ex", line: 84]},
  {:gen_server, :try_handle_info, 3, [file: ~c"gen_server.erl", line: 2345]}
]

Environment

• Elixir & Erlang version (elixir -v): 1.18.2
• Agent version (mix deps | grep new_relic_agent): 1.33.0

[binaryseed]

Thanks for the report, got a PR up to handle the case