Remove another mention of "import string".

The file itself still mentions Python 1.5.1,
so it might need further updates.

Tools/freeze/win32.html

@@ -48,10 +48,9 @@
 <H4>Source Code</H4><DIR>
 <DIR>
 
-<CODE><P>import string</P>
-<P>import sys</P>
+<CODE><P>import sys</P>
 <P>&nbsp;</P>
-<P>print string.join( ["Hello", "world"] + sys.argv[1:] )</P></DIR>
+<P>print " ".join( ["Hello", "world"] + sys.argv[1:] )</P></DIR>
 </DIR>
 
 </CODE><H4>Command Line used</H4><DIR>