filter: don't search in background on mobile

I experienced weird crashes that seemed timing-related when
using the filter. Therefore, remove the multi-threading thing.
So far no more crashes, but keep a close eye on that.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

mobile-widgets/qml/main.qml

@@ -60,21 +60,11 @@ Kirigami.ApplicationWindow {
 		busy.running = true
 	}
 
-	function showBusyAndDisconnectModel() { // this is used by QMLManager when operating the filter
-		busy.running = true
-		diveList.diveListModel = null
-	}
-
 	function hideBusy() {
 		busy.running = false
 		showPassiveNotification("", 10) // this hides a notification messssage that's still shown
 	}
 
-	function hideBusyAndConnectModel() { // this is used by QMLManager when done filtering
-		busy.running = false
-		diveList.diveListModel = diveTripModel
-	}
-
 	function returnTopPage() {
 		for (var i=pageStack.depth; i>1; i--) {
 			pageStack.pop()