fix(router): don't let an unmatched model field block autoswap (#2384) (#2387)

In autoswap mode, a POST to /v1/completions or /v1/chat/completions
carrying a `model` name that is not an entry in the admin dir set
`model_switch_pass = True` before checking the whitelist. No swap was
performed, but the flag suppressed the request-type dispatch below it,
so the text model was never loaded on demand.

The same requests without a `model` field, and every other model type
(stt/tts/embed/music/image), skip that branch entirely and load fine --
which is why only chat was affected, and why sending one model-less
request worked around it. It also recurs after --adminunloadtimeout
fires, since the "nomodel" state is recovered from by that same
dispatch.

Only set the flag on the path that actually issues the reload.

koboldcpp.py

@@ -4982,11 +4982,11 @@ class KcppProxyHandler(http.server.BaseHTTPRequestHandler):
                     is_different_model = True
 
                 if is_different_model or was_auto_unloaded:
-                    model_switch_pass = True
                     whitelist = get_current_admindir_list() # see if its an allowed swap
                     if was_auto_unloaded and not model_name:
                         model_name = "initial_model"
                     if is_different_model and (model_name in whitelist):
+                        model_switch_pass = True # only claim the request if we really are swapping
                         global_memory["last_active_timestamp"] = datetime.now()
                         global_memory["triggered_sleeping"] = False
                         reqbody = json.dumps({"filename":model_name})