fix(lua): Array indexes for get/setFlightMode and getCurve (#2567)

* Lua array indexes start at 1

* LUA model.setFlightMode: use array index to compute trim index

This allows for providing an incomplete table like this:
```
-- Disable T5 & T6 on FM0
modes = {}
modes[5] = 31
modes[6] = 31
t = {}
t["trimsModes"] = modes
model.setFlightMode(0, t)
```

* Remove warning & cleanup

* Fix trim value constraints in model.setFlightMode()

radio/src/lua/api_general.cpp

@@ -1187,7 +1187,7 @@ static int luaGhostTelemetryPop(lua_State * L)
     lua_newtable(L);
     for (uint8_t i=0; i<length-2; i++) {
       luaInputTelemetryFifo->pop(data);
-      lua_pushinteger(L, i+1);
+      lua_pushinteger(L, i + 1);
       lua_pushinteger(L, data);
       lua_settable(L, -3);
     }
@@ -2587,7 +2587,7 @@ static int luaSources(lua_State * L)
 static int luaGetOutputValue(lua_State * L)
 {
   mixsrc_t idx = luaL_checkinteger(L, 1);
-  if (idx >= 0 && idx < MAX_OUTPUT_CHANNELS) {
+  if (idx < MAX_OUTPUT_CHANNELS) {
     lua_pushinteger(L, channelOutputs[idx]);
   } else {
     lua_pushinteger(L, 0);