fix: replace filterNotNull() with null check

app/src/main/java/com/geeksville/mesh/model/UIState.kt

@@ -40,7 +40,6 @@ import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
-import kotlinx.coroutines.flow.filterNotNull
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.flow.flatMapLatest
 import kotlinx.coroutines.flow.launchIn
@@ -157,8 +156,9 @@ class UIViewModel @Inject constructor(
             _ourNodeInfo.value = it
         }.launchIn(viewModelScope)
 
-        combine(meshLog, requestId.filterNotNull()) { packet, id ->
-            _packetResponse.value = packet.firstOrNull { it.meshPacket?.decoded?.requestId == id }
+        combine(meshLog, requestId) { packet, requestId ->
+            if (requestId != null) _packetResponse.value =
+                packet.firstOrNull { it.meshPacket?.decoded?.requestId == requestId }
         }.launchIn(viewModelScope)
 
         debug("ViewModel created")