adds setting screen

src/service/interface/xml/net.buzzert.kordophonecd.Server.xml

@@ -80,12 +80,6 @@
         <property name="ServerURL" type="s" access="readwrite"/>
         <property name="Username"  type="s" access="readwrite"/>
 
-        <!-- Secret-Service handle (object path) -->
-        <property name="CredentialItem" type="o" access="readwrite">
-            <annotation name="org.freedesktop.DBus.Property.EmitsChangedSignal"
-                        value="true"/>
-        </property>
-
         <!-- helpers for atomic updates -->
         <method name="SetServer">
             <arg name="url"  type="s" direction="in"/>