Ensure default option for pruning/disposing of cache sources is set properly (#3901)

Author: WolframPfeifer

keyext.caching/src/main/java/de/uka/ilkd/key/gui/plugins/caching/settings/CachingSettingsProvider.java

@@ -80,7 +80,7 @@ public CachingSettingsProvider() {
                 When a referenced proof is pruned, this is what happens to
                  all cached branches that reference it.""",
             0, x -> {
-            }, PRUNE_REOPEN, PRUNE_COPY);
+            }, PRUNE_COPY, PRUNE_REOPEN);
     }
 
     @Override

keyext.caching/src/main/java/de/uka/ilkd/key/gui/plugins/caching/settings/ProofCachingSettings.java

@@ -39,12 +39,12 @@ public class ProofCachingSettings extends AbstractPropertiesSettings {
      * Behaviour when disposing a proof that is referenced elsewhere.
      */
     private final AbstractPropertiesSettings.PropertyEntry<String> dispose =
-        createStringProperty(DISPOSE_KEY, "");
+        createStringProperty(DISPOSE_KEY, DISPOSE_COPY);
     /**
      * Behaviour when pruning a proof that is referenced elsewhere.
      */
     private final AbstractPropertiesSettings.PropertyEntry<String> prune =
-        createStringProperty(PRUNE_KEY, "");
+        createStringProperty(PRUNE_KEY, PRUNE_COPY);
 
     public ProofCachingSettings() {
         super("ProofCaching");