return nil,err on git material fetch error (#4857)

Author: prakash100198

pkg/pipeline/CiHandler.go

@@ -430,7 +430,7 @@ func (impl *CiHandlerImpl) FetchMaterialsByPipelineId(pipelineId int, showAll bo
 		impl.Logger.Debugw("commits for material ", "m", m, "commits: ", changesResp)
 		if apiErr != nil {
 			impl.Logger.Warnw("git sensor FetchChanges failed for material", "id", m.Id)
-			return []pipelineConfig.CiPipelineMaterialResponse{}, apiErr
+			return nil, apiErr
 		}
 		ciMaterialHistoryMap[m] = changesResp
 	}
@@ -459,7 +459,7 @@ func (impl *CiHandlerImpl) FetchMaterialsByPipelineId(pipelineId int, showAll bo
 	regexMaterials, err := impl.ciPipelineMaterialRepository.GetRegexByPipelineId(pipelineId)
 	if err != nil {
 		impl.Logger.Errorw("regex ciMaterials fetch failed", "err", err)
-		return []pipelineConfig.CiPipelineMaterialResponse{}, err
+		return nil, err
 	}
 	for _, k := range regexMaterials {
 		r := pipelineConfig.CiPipelineMaterialResponse{