fix: Simplify and better safeguard settings patch.

Handle the case where the OPEN_EDX_FILTERS_CONFIG setting might not
exist and simplify the code for adding/updating the new step to the
correct pipeline.

Author: feanil

plugins/tutor-contrib-ltistore/tutor_ltistore/patches/openedx-common-settings

@@ -1,21 +1,17 @@
 
 # Add the lti store filter to the filter list, creating the configuration if it doesn't
 # exist but updating it if it does exist.
-
 _filter_name = 'org.openedx.xblock.lti_consumer.configuration.listed.v1'
+_step_name = 'lti_store.pipelines.GetLtiConfigurations'
 
-# Get or create the filter and pipeline list for the filter we care about
-_filter_to_update = OPEN_EDX_FILTERS_CONFIG.get(_filter_name, {})
-_pipeline_list = _filter_to_update.get('pipeline', [])
-
-# Update the list to add our new filter.
-_pipeline_list.append('lti_store.pipelines.GetLtiConfigurations')
-
-# Replace the existing setting with the updated version from the bottom up.
-# We do this because we might have created the object via the gets above. In
-# which case, the parent object would not have a reference to it.
-_filter_to_update['pipeline'] = _pipeline_list
-# Just override this, we don't care if it's there or not.
-_filter_to_update['fail_silently'] = False
-OPEN_EDX_FILTERS_CONFIG[_filter_name] = _filter_to_update
+try:
+    not OPEN_EDX_FILTERS_CONFIG
+except NameError:  # OPEN_EDX_FILTERS_CONFIG is not defined
+    OPEN_EDX_FILTERS_CONFIG = {}
 
+if not OPEN_EDX_FILTERS_CONFIG.get(_filter_name):
+    OPEN_EDX_FILTERS_CONFIG[_filter_name] = {
+        "fail_silently": False,
+        "pipeline": [],
+    }
+OPEN_EDX_FILTERS_CONFIG[_filter_name]["pipeline"].append(_step_name)