Example: 
[BLANK.DWG.gz](https://github.com/LibreDWG/libredwg/files/11677294/BLANK.DWG.gz)

Convert to JSON:
```dwgread -o BLANK.json BLANK.DWG```

In JSON is:
```
...
"MENU": "acad\u0000e\u0000g\offic\u0000",
...
```

Conversion back:
```dwgwrite BLANK.json```
returns:
```
ERROR: Invalid json. jsmn error at pos: 1608 (...   "MENU": "acad\u000 ...)
ERROR 0x800
```

Probably missing escape for ```\```
Wrong conversion to JSON for MENU header variable
This is a GitHub Issue
repo:libredwg
owner:LibreDWG
Title : Wrong conversion to JSON for MENU header variable
Issue date:

--- start body ---
Example: 
[BLANK.DWG.gz](https://github.com/LibreDWG/libredwg/files/11677294/BLANK.DWG.gz)

Convert to JSON:
```dwgread -o BLANK.json BLANK.DWG```

In JSON is:
```
...
"MENU": "acad\u0000e\u0000g\offic\u0000",
...
```

Conversion back:
```dwgwrite BLANK.json```
returns:
```
ERROR: Invalid json. jsmn error at pos: 1608 (...   "MENU": "acad\u000 ...)
ERROR 0x800
```

Probably missing escape for ```\```
--- end body ---
