Trac Ticket #497 - Escaped character cannot be used in the substring search filter
Bug description: Previous commit de8fd7d0e596e4de885b4dda6bf5329469880c45
for Ticket 328 introduced this bug. Only a string format filter
for logging needs to be escaped, but the above commit accidentally
applied the escaped filter to the real filter.
Fix description: This patch did undo the escape on the real filter.