Update comment about why postmaster doesn't get an icon.

src/backend/Makefile

@@ -5,12 +5,12 @@
 # Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
 # Portions Copyright (c) 1994, Regents of the University of California
 #
-# $PostgreSQL: pgsql/src/backend/Makefile,v 1.143 2010/05/12 21:42:21 momjian Exp $
+# $PostgreSQL: pgsql/src/backend/Makefile,v 1.144 2010/05/12 23:48:36 momjian Exp $
 #
 #-------------------------------------------------------------------------
 
 PGFILEDESC = "PostgreSQL Server"
-# it is unclear that this should be labeled as an executable
+# This is a daemon process, which is why it is not labeled as an executable
 #PGAPPICON=win32
 
 subdir = src/backend