Oomph: Fix JFX SDK path

Issue-Ref: 3837
Signed-off-by: Alexander Diewald <diewald@fortiss.org>

oomph/af3.setup

@@ -178,8 +178,8 @@
     <setupTask
         xsi:type="setup:PreferenceTask"
         id="jfx.installation.setting"
-        key="/instance/org.eclipse.fx.ide.ui/javafx-sdk-${jfx.installation.version}"
-        value="${installation.location/javafx-sdk}-${jfx.installation.version}/lib/"/>
+        key="/instance/org.eclipse.fx.ide.ui/javafx-sdk"
+        value="${installation.location}/javafx-sdk-${jfx.installation.version}/lib/"/>
   </setupTask>
   <setupTask
       xsi:type="setup:CompoundTask"