Fixed search keyword list; Fixes #4187

Author: xoriole

Tribler/Core/CacheDB/SqliteCacheDBHandler.py

@@ -907,11 +907,15 @@ def relevance_score_remote_torrent(self, torrent_name):
         """
         if self.latest_matchinfo_torrent is None:
             return 0.0
-        matchinfo, keywords = self.latest_matchinfo_torrent
+        matchinfo, raw_keywords = self.latest_matchinfo_torrent
 
         # Make sure the strings are utf-8 encoded
-        if not isinstance(keywords, text_type):
-            keywords = keywords.decode('raw_unicode_escape')
+        keywords = []
+        for keyword in raw_keywords:
+            if not isinstance(keyword, text_type):
+                keyword = keyword.decode('raw_unicode_escape')
+            keywords.append(keyword)
+
         if not isinstance(torrent_name, text_type):
             torrent_name = torrent_name.decode('raw_unicode_escape')