Save the plugins cache as early as possible

This rgeatly reduces the changes that it's generated more than once,
if there are multiple concurrent VLC's, or if VLC crashes before exit.

src/modules/modules.c

@@ -164,8 +164,6 @@ void module_EndBank( vlc_object_t *p_this, bool b_plugins )
     vlc_mutex_unlock( &module_lock );
 
 #ifdef HAVE_DYNAMIC_PLUGINS
-    if( p_bank->b_cache )
-        CacheSave( p_this, p_bank );
     while( p_bank->i_loaded_cache-- )
     {
         if( p_bank->pp_loaded_cache[p_bank->i_loaded_cache] )
@@ -215,6 +213,8 @@ void module_LoadPlugins( vlc_object_t * p_this, bool b_cache_delete )
         if( p_module_bank->b_cache || b_cache_delete )
             CacheLoad( p_this, p_module_bank, b_cache_delete );
         AllocateAllPlugins( p_this, p_module_bank );
+        if( p_module_bank->b_cache )
+            CacheSave( p_this, p_bank );
         config_UnsortConfig ();
         config_SortConfig ();
     }