If retweets are disabled then check the summary for twitter posts

inbox.py

@@ -567,6 +567,22 @@ def inbox_permitted_message(domain: str, message_json: {},
     return True
 
 
+def _reject_twitter_summary(base_dir: str, nickname: str, domain: str,
+                            summary: str) -> bool:
+    """Returns true if the post should be rejected due to twitter
+    existing within the summary
+    """
+    remove_twitter = \
+        acct_dir(base_dir, nickname, domain) + '/.removeTwitter'
+    if not os.path.isfile(remove_twitter):
+        return False
+    summary_lower = summary.lower()
+    if 'twitter' in summary_lower or \
+       'birdsite' in summary_lower:
+        return True
+    return False
+
+
 def save_post_to_inbox_queue(base_dir: str, http_prefix: str,
                              nickname: str, domain: str,
                              post_json_object: {},
@@ -655,6 +671,13 @@ def save_post_to_inbox_queue(base_dir: str, http_prefix: str,
             if debug:
                 print('WARN: post was filtered out due to content')
             return None
+        if summary_str:
+            if _reject_twitter_summary(base_dir, nickname, domain,
+                                       summary_str):
+                if debug:
+                    print('WARN: post was filtered out due to ' +
+                          'twitter content')
+                return None
 
     original_post_id = None
     if post_json_object.get('id'):