Remove _profile from start slice job parameters

Instead, the start slice job searches for the container stack itself.

Contributes to issue CURA-1278.

plugins/CuraEngineBackend/CuraEngineBackend.py

@@ -154,7 +154,7 @@ class CuraEngineBackend(Backend):
         self._slicing = True
         self.slicingStarted.emit()
 
-        job = StartSliceJob.StartSliceJob(self._profile, self._socket)
+        job = StartSliceJob.StartSliceJob(self._socket)
         job.start()
         job.finished.connect(self._onStartSliceCompleted)
 

plugins/CuraEngineBackend/StartSliceJob.py

@@ -31,11 +31,11 @@ class GcodeStartEndFormatter(Formatter):
 
 ##  Job that handles sending the current scene data to CuraEngine
 class StartSliceJob(Job):
-    def __init__(self, profile, socket):
+    def __init__(self, socket):
         super().__init__()
 
         self._scene = Application.getInstance().getController().getScene()
-        self._profile = profile
+        self._settings = Application.getInstance().getGlobalContainerStack()
         self._socket = socket
 
     ##  Runs the job that initiates the slicing.