* Don't try to concatenate a blank dispText (display nil instead)

diff --git a/PerfectRaid_Buffs.lua b/PerfectRaid_Buffs.lua
index 2312dd0..e805dd2 100644
--- a/PerfectRaid_Buffs.lua
+++ b/PerfectRaid_Buffs.lua
@@ -738,7 +738,7 @@ function Buffs:UpdateBuffTable()
 			local tbl = {}
 			tbl.buffname = entry.buffname
 			tbl.groupname = entry.groupname
-			tbl.colortext = "|cFF"..entry.color..entry.disptext.."|r"
+			tbl.colortext = "|cFF"..entry.color..tostring(entry.disptext).."|r"
 			tbl.missing = entry.missing
 			tbl.strict = entry.strict
 			tbl.cond = {string.split(",", entry.conds)}