docs: Note that relative URL's are no longer supported in redirects.

git-svn-id: https://simplesamlphp.googlecode.com/svn/trunk@2704 44740490-163a-0410-bde0-09ae8108e29a

docs/simplesamlphp-upgrade-notes-1.7.txt

@@ -7,3 +7,6 @@ Upgrade notes for simpleSAMLphp 1.7
   * There have been several changes to the internal API.
     Most of the changes will not be noticed by the application using simpleSAMLphp.
     See the changelog for more details about the changes.
+  * Relative redirects are no longer supported.
+    If your application passes relative URL's to the `SimpleSAML_Utilities::redirect()`-function, it will no longer work.
+    This also applies if you pass relative URL's to other functions that do redirects.