character encoding issue with SBML for WP5039
The SBML generates fine with the webservice, but the resulting XML is not. `xmllint` reports:
```shell
$ xmllint --noout sbml/WP5039.sbml
sbml/WP5039.sbml:13083: parser error : Input is not proper UTF-8, indicate encoding !
Bytes: 0xDF 0x20 0x70 0x72
<p>High levels of viral load stimulate TGF� production, which is locally secrete
^
```
And `xpath` reports:
```shell
$ xpath -e "/sbml/model/notes/body/p/text()" sbml/WP5039.sbml
not well-formed (invalid token) at line 13083, column 42, byte 824587:
<notes>
<body xmlns="http://www.w3.org/1999/xhtml">
<p>High levels of viral load stimulate TGFß production, which is locally secreted.
=========================================^
</p>
at /usr/lib/x86_64-linux-gnu/perl5/5.32/XML/Parser.pm line 187.
```
issue