Fix IndexOutOfRangeException when using get-desc with SetupProcess

Fixed the setup process tool trying to use too many command line
arguments. The out directory is passed on stdin not as a command
line argument.

Mono.Addins.SetupProcess/SetupProcessTool.cs

@@ -62,7 +62,7 @@ public static int Main (string [] args)
 					}
 				case "get-desc":
 					var outFile = Console.In.ReadLine ();
-					reg.ParseAddin (monitor, args [2], args [3]);
+					reg.ParseAddin (monitor, args [2], outFile);
 					break;
 				}
 			} catch (Exception ex) {