Improve shutdown

1. close logfile as last action
2. Fix `plugins_shutdown()` accessing `((ProfPlugin*)curr->data)->lang`
   after `curr->data` had already potentially been free'd.

Signed-off-by: Steffen Jaeckel <jaeckel-floss@eyet-services.de>

src/plugins/plugins.c

@@ -932,21 +932,23 @@ void
 plugins_shutdown(void)
 {
     GList* values = g_hash_table_get_values(plugins);
-    GList* curr = values;
+    GList *curr = values, *next;
 
     while (curr) {
+        next = g_list_next(curr);
 #ifdef HAVE_PYTHON
-        if (((ProfPlugin*)curr->data)->lang == LANG_PYTHON) {
+        if (curr && ((ProfPlugin*)curr->data)->lang == LANG_PYTHON) {
             python_plugin_destroy(curr->data);
+            curr = NULL;
         }
 #endif
 #ifdef HAVE_C
-        if (((ProfPlugin*)curr->data)->lang == LANG_C) {
+        if (curr && ((ProfPlugin*)curr->data)->lang == LANG_C) {
             c_plugin_destroy(curr->data);
+            curr = NULL;
         }
 #endif
-
-        curr = g_list_next(curr);
+        curr = next;
     }
     g_list_free(values);
 #ifdef HAVE_PYTHON

src/profanity.c

@@ -256,9 +256,9 @@ _shutdown(void)
     accounts_close();
     tlscerts_close();
     log_stderr_close();
-    log_close();
     plugins_shutdown();
     cmd_uninit();
     ui_close();
     prefs_close();
+    log_close();
 }