SvtBroadcaster no need to unique

SvtListener already enforces this

Change-Id: I0389668af12013addfdbeec7a5e92a9d374193dc
Reviewed-on: https://gerrit.libreoffice.org/61150
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

include/svl/broadcast.hxx

@@ -74,6 +74,7 @@ public:
     void PrepareForDestruction();
 
 private:
+    /// contains only one of each listener, which is enforced by SvtListener
     mutable ListenersType maListeners;
 
     /// When the broadcaster is about to die, collect listeners that asked for removal.

svl/source/notify/broadcast.cxx

@@ -28,16 +28,12 @@ void SvtBroadcaster::Normalize() const
     if (!mbNormalized)
     {
         std::sort(maListeners.begin(), maListeners.end());
-        ListenersType::iterator itUniqueEnd = std::unique(maListeners.begin(), maListeners.end());
-        maListeners.erase(itUniqueEnd, maListeners.end());
         mbNormalized = true;
     }
 
     if (!mbDestNormalized)
     {
         std::sort(maDestructedListeners.begin(), maDestructedListeners.end());
-        ListenersType::iterator itUniqueEnd = std::unique(maDestructedListeners.begin(), maDestructedListeners.end());
-        maDestructedListeners.erase(itUniqueEnd, maDestructedListeners.end());
         mbDestNormalized = true;
     }
 }