added CURLOPT_PORT test when using proxy

tests/data/test523

+<info>
+<keywords>
+HTTP
+HTTP GET
+CURLOPT_PORT
+CURLOPT_PROXY
+</keywords>
+</info>
+
+#
+# Server-side
+<reply>
+<data nocheck=1>
+HTTP/1.1 200 OK swsclose
+Date: Thu, 09 Nov 2010 14:49:00 GMT
+Server: test-server/fake
+Last-Modified: Tue, 13 Jun 2000 12:10:00 GMT
+ETag: "21025-dc7-39462498"
+Accept-Ranges: bytes
+Content-Length: 6
+
+hello
+</data>
+</reply>
+
+#
+# Client-side
+<client>
+<server>
+http
+</server>
+<tool>
+lib523
+</tool>
+ <name>
+HTTP GET with proxy and CURLOPT_PORT
+ </name>
+# first URL then proxy
+ <command>
+http://www.haxx.se:999/523 http://%HOSTIP:%HTTPPORT 
+</command>
+</client>
+
+#
+# Verify data after the test has been "shot"
+<verify>
+<strip>
+^User-Agent:.*
+</strip>
+<protocol>
+GET http://www.haxx.se:19999/523 HTTP/1.1
+Authorization: Basic eHh4Onl5eQ==
+Host: www.haxx.se:19999
+Pragma: no-cache
+Accept: */*
+
+</protocol>
+<stdout>
+hello
+</stdout>
+</verify>