Fix a stack trace that keeps being emailed:

Author Mere <rift@dokein.co.uk>
Author date 2013-08-26 10:15:02
Author local date 2013-08-26 11:15:02 +0100
Committer Mere <rift@dokein.co.uk>
Committer date 2013-08-26 10:15:02
Committer local date 2013-08-26 11:15:02 +0100
Commit e644de19e67a065d88434dd51edc3fd852e58a2b
Tree 944f37c1eacf33bd8be0ec25188786bb8e9b61ce
Parent e156bbae2b432440e2a75e0a8d949ae634b02bee
Fix a stack trace that keeps being emailed:
Error: MereHealingFrames/BuffManager.lua:100: attempt to index local ''newBuffSet'' (a nil value)
    In MereHealingFrames / MereHealingFrames.SavedVars.Load, event Event.Addon.SavedVariables.Load.End
stack traceback:
    [C]: in function ''__index''
    MereHealingFrames/BuffManager.lua:100: in function ''RefreshBuffSet''
    MereHealingFrames/BuffManager.lua:71: in function ''new''
    MereHealingFrames/RaidManagement.lua:107: in function ''new''
    MereHealingFrames/RaidManagement.lua:382: in function ''LoadRaid''
    MereHealingFrames/SavedVariables.lua:59: in function <MereHealingFrames/SavedVariables.lua:19>

The code now creates an empty buffset if it can't find one from the saved vars.