Fix search repeating when the end has been reached

src/api.nim

@@ -168,6 +168,11 @@ proc getGraphTweetSearch*(query: Query; after=""): Future[Timeline] {.async.} =
   result = parseGraphSearch[Tweets](js, after)
   result.query = query
 
+  # when no more items are available the API just returns the last page in
+  # full. this detects that and clears the page instead.
+  if after.len > 0 and after[0..<64] == result.bottom[0..<64]:
+    result.content.setLen(0)
+
 proc getGraphUserSearch*(query: Query; after=""): Future[Result[User]] {.async.} =
   if query.text.len == 0:
     return Result[User](query: query, beginning: true)