server: request_lead was doing some work that mark_start_singing shou…

…ld have done

When someone request the lead, this should not attempt to destroy the previous song. Other people might still be listening to it, and there could be something going on with the recording. That should wait until someone starts singing.

Fixes #201 (pretty sure)

server.py

@@ -806,7 +806,7 @@ def handle_special(query_params, server_clock, user=None, client_read_clock=None
         state.requested_track = requested_track
 
     if query_params.get("mark_start_singing", None):
-        # Always clear events at the start of a new song.
+        clear_whole_buffer()
         events.clear()
 
         # XXX: There is some confusion over exactly where the start marker should go, but it should be a value that we are guaranteed to have, so the song doesn't fail to start. (So not the write clock.)
@@ -1074,14 +1074,9 @@ def handle_post(in_json, in_data) -> Tuple[Any, str]:
     #   accident.
     if query_params.get("request_lead", None) and not state.server_controlled:
         assign_delays(userid)
-        state.song_start_clock = 0
-        state.song_end_clock = 0
-
-        state.metronome_on = False
         state.leader = userid
         state.lyrics = ""
         sendall("lyrics", "")
-        clear_whole_buffer()
 
     # Handle all operations that do not require a userid
     handle_special(query_params, server_clock, user, client_read_clock)