Revert "Fix Per Object Settings toolbutton enabled state on startup"

This reverts commit 8d7df76aa19009192247d5fb14babbdf9d7c6202.

Contributes to CURA-901

plugins/PerObjectSettingsTool/PerObjectSettingsTool.py

@@ -16,7 +16,6 @@ class PerObjectSettingsTool(Tool):
 
         self.setExposedProperties("Model", "SelectedIndex")
 
-        Application.getInstance().getController().toolEnabledStateRequest.connect(self._onToolEnabledStateRequested)
         Preferences.getInstance().preferenceChanged.connect(self._onPreferenceChanged)
 
     def event(self, event):
@@ -41,9 +40,6 @@ class PerObjectSettingsTool(Tool):
         index = self.getModel().find("id", selected_object_id)
         return index
 
-    def _onToolEnabledStateRequested(self):
-        self._onPreferenceChanged("cura/active_mode")
-
     def _onPreferenceChanged(self, preference):
         if preference == "cura/active_mode":
             enabled = Preferences.getInstance().getValue(preference)==1