Update changelog.

docs/simplesamlphp-changelog.md

@@ -29,6 +29,35 @@ Released TBD
 ### Interoperability
   * The minimum PHP version required is now 5.6.
 
+## Version 1.17.3
+
+Released 2019-07-10
+
+  * Resolved a security issue that could lead to a reflected XSS.  See
+    [SSPSA 201907-01](https://simplesamlphp.org/security/201907-01).
+  * Add new options `session.cookie.samesite` and `language.cookie.samesite` that can be
+    used to set a specific value for the cookies' SameSite attribute. The default it not
+    to set it.
+  * Upgraded jQuery to version 3.4.
+  * HHVM is no longer supported.
+  * Fixed a bug (#926) where dynamic metadata records where not loaded from a database.
+  * Fixed an issue when an error occurs during a passive authentication request.
+  * Handle duplicate insertions for SQL Server.
+  * Fix a bug in Short SSO Interval warning filter.
+  * Apply a workaround for SIGSEGVs during session creation with PHP-FPM 7.3.
+
+### adfs
+  * Fixed a missing option to supply a passphrase for the ADFS IDP signing certificate.
+
+### authlinkedin
+  * This module has been removed now that LinkedIn no longer supports OAuth1.
+    If you relied on this module, you may consider migrating to the
+    [authoauth2 module](https://github.com/cirrusidentity/simplesamlphp-module-authoauth2).
+    A migration guide for LinkedIn authentication is included in their README.
+
+### saml
+  * Added support for per-IDP configurable `AuthnContextClassRef`/`AuthnContextComparison`.
+
 ## Version 1.17.2
 
 Released 2019-04-02