fix(ui): preserve shared_preload_libraries value on config page reload

Issue from the email support:

every time the user refreshes the configuration page in the UI, plrust sneaks its way back in to the shared_preload_libraries list

When using SE images, the fetchSeImages() function was unconditionally overwriting the saved shared_preload_libraries value with the preset from Platform's SE image metadata. This caused user-saved values to be replaced with presets every time the configuration page loaded

The fix preserves the saved configuration value during initial render