XWIKI-7692: java.lang.ClassCastException when viewing installed extensions

Safer installed extension namespaces

xwiki-platform-core/xwiki-platform-extension/xwiki-platform-extension-script/src/main/java/org/xwiki/extension/script/internal/safe/SafeInstalledExtension.java

@@ -67,7 +67,7 @@ public boolean isInstalled(String namespace)
     @Override
     public Collection<String> getNamespaces()
     {
-        return getWrapped().getNamespaces();
+        return safe(getWrapped().getNamespaces());
     }
 
     @Override