Explicitly require PKCE.

Author: dkocher

hub/src/test/resources/Katta Server.cyberduckprofile

@@ -32,9 +32,11 @@
         <string>${oauth.handler.scheme}:oauth</string>
         <key>OAuth Client Secret</key>
         <string/>
+        <key>OAuth PKCE</key>
+        <true/>
         <key>Password Configurable</key>
         <false/>
         <key>Username Configurable</key>
         <false/>
     </dict>
-</plist>
+</plist>