[Manual Search] Make URL column unique in providers table in cache database

[fernandog]

Fix dupe items

Need erase cache.db or should do a ALTER TABLE do change existing cache.db to use UNIQUE?

@labrys @p0psicles @medariox @OmgImAlexis this PR fixed issue..... but we already have this in code but it seems its not working!

            # add unique index to prevent further dupes from happening if one does not exist
            self.action("CREATE UNIQUE INDEX IF NOT EXISTS idx_url ON [" + providerName + "] (url)")

Seems code already remove dups. but only at boot:

                 for cur_dupe in sql_results:
                     self.action("DELETE FROM [" + providerName + "] WHERE url = ?", [cur_dupe["url"]])

I know SQL but not an expert

[fernandog]

I think it worked. See first item: Before 161 seeds than 168

First search

After forced results

[fernandog]

will merge for now