Fixed a Thread setup, no reported bugs on the "error" yet.

git-svn-id: http://svn.code.sf.net/p/greenshot/code/trunk@2081 7dccd23d-a4a3-4e1f-8c07-b4c1b4018ab4

Greenshot/Forms/MainForm.cs

@@ -354,6 +354,7 @@ namespace Greenshot {
 			});
 			pluginInitThread.Name = "Initialize plug-ins";
 			pluginInitThread.IsBackground = true;
+			pluginInitThread.SetApartmentState(ApartmentState.STA);
 			pluginInitThread.Start();
 
 			SoundHelper.Initialize();