Avoid setting maxfiles for a remote asterisk

Setting maxfiles (maximum number of open files) has no practical
effect on a remote asterisk (rasterisk, rasterisk -x).

It has an ill effect of printing an extra message, which
may be annoying in case of -x.

ASTERISK-27105 #close

Change-Id: Iaf9eb344e4b4b517df91b736b27ec55f6a6921a2