Prevent SLA settings from getting wiped out on reload

Prevent SLA settings from getting wiped out on reload

If SLA was reloaded without the config file being changed, current settings got
wiped out before the SLA reload code decided it wasn't going to reload the file
since nothing was changed.  Moving the settings reset later in the reload
process fixes this.

(closes issue AST-744)
........

Merged revisions 350023 from http://svn.asterisk.org/svn/asterisk/branches/1.8

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/10@350024 65c4cc65-6c06-0410-ace0-fbb531ad65f3