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/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();
 }