fix error with description

Author: issamansur

crawler.py

@@ -46,7 +46,7 @@
                 repo_set.add(repo.repository.full_name)
                 print("{0}".format(repo.repository))
 
-                innersource_repo = repo.as_dict()
+                innersource_repo: dict = repo.as_dict()
                 innersource_repo["_InnerSourceMetadata"] = {}
 
                 # fetch innersource.json
@@ -79,6 +79,9 @@
                 # fetch repository topics
                 repo_topics = repo.repository.topics()
                 innersource_repo["_InnerSourceMetadata"]["topics"] = repo_topics.names
+                
+                # set description = '' if no exist
+                innersource_repo.set_default('description', '')
 
                 # calculate score
                 innersource_repo["score"] = repo_activity.score.calculate(