When a multi line result is submitted via the command pipe, any multi line
output is escaped to a actual string '\n', because any external command only
can be a single line.
Example:
[1432735140] PROCESS_SERVICE_CHECK_RESULT;host;service;3;Test1\nTest2|test=1
We need to unescape this values, just like we use to escape multi line output
for IDO and status.dat.
fixes#9324
Signed-off-by: Michael Friedrich <michael.friedrich@netways.de>