chore(deps): use released version of PHP client

fixes composer installation with minimum-stability: stable

composer.json

@@ -5,6 +5,6 @@
     "license": "AGPL-3.0",
     "require": {
         "simplesamlphp/composer-module-installer": "~1.0",
-        "privacyidea/privacyidea-php-client": "dev-master"
+        "privacyidea/privacyidea-php-client": "~0.9.3"
     }
 }