fix(Files): use prepare statement for path_hash in propagator

[blizzz]

Summary

The other day I had to analyze SQL queries. And in the log I found entries like:

UPDATE "oc_filecache" SET "mtime" = GREATEST("mtime", $1), "etag" = $2 
WHERE ("storage" = $3) 
    AND ("path_hash" IN ('0123456789abcdef0123456789abcdef', '123456789abcdef0123456789abcdef0', '23456789abcdef0123456789abcdef01', '3456789abcdef0123456789abcdef012', '456789abcdef0123456789abcdef0123', '56789abcdef0123456789abcdef01234', '6789abcdef0123456789abcdef012345', '789abcdef0123456789abcdef0123456')) 

As you see, some parameters where having placeholders (originating from use of prepared statements) while the IN list had not. So it was not possible to simply sum up this query, because it contained differing values.

Checklist

• Code is properly formatted
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