Content.json write error: false This file still in sync [SKIPPED] content.json

### Step 1: Please describe your environment

* ZeroNet version: 4455
* Operating system: W10
* Web browser: FF beta

### Step 2: Describe the problem:

Hello, suddenly when i tried to publish changes on my zeroblog clone, it shown on site error:

> Content.json write error: false

and prompt:

> This file still in sync, if you write it now, then the previous content may be lost. [ Write content anyway ]

in debug log is:

> INFO Site:1abc..def Opening site data directory: C:/ZeroNet-win-dist-win64/data/1abc...def/...
> INFO Site:1abc..def - [SKIPPED] content.json

same for:
"[SKIPPED] data/users/content.json"
"[SKIPPED] data/data.json-old"

> INFO Site:1abc..def Signing content.json...
> INFO Site:1abc..def Saving to content.json...
> INFO Site:1abc..def File content.json signed!

then i reload the site (F5) and after two hours without restarting or updating Zeronet, the publishing on that site works again without any messages mentioned above.

HDD has enough disk space. Though my RAM was exhausted.

Maybe you have clue what can cause this. If no and i can do something to discover more details, let me know and i will provide it.

首先复现 ZeroBlog 克隆的发布流程，并检查 content.json、data/users/content.json 和 data/data.json-old 的调试日志条目，尤其是 [SKIPPED] 消息。比较 RAM 耗尽时以及之后发布成功后的行为；完成的标准是确定一个可靠的原因或复现方法，并记录由此产生的修复或诊断证据。

由索引模型根据 Issue 内容生成。