Don't remove mentions for public posts

posts.py

@@ -1446,6 +1446,7 @@ def _createPostBase(baseDir: str,
 
     postContext = getIndividualPostContext()
 
+    if not isPublic:
         # make sure that CC doesn't also contain a To address
         # eg. To: [ "https://mydomain/users/foo/followers" ]
         #     CC: [ "X", "Y", "https://mydomain/users/foo", "Z" ]
@@ -1458,8 +1459,8 @@ def _createPostBase(baseDir: str,
                     break
         for ccRemoval in removeFromCC:
             toCC.remove(ccRemoval)
-
-    if inReplyTo and isPublic:
+    else:
+        if inReplyTo:
             # If this is a public post then get the actor being
             # replied to end ensure that it is within the CC list
             replyActor = getActorFromInReplyTo(inReplyTo)