New review comment by paper42 on void-packages repository

https://github.com/void-linux/void-packages/pull/41844#discussion_r1123699454

Comment:
a workaround like this could work, but I didn't test it
```suggestion
-#  if !defined(_GNU_SOURCE) || (!(~_GNU_SOURCE+1) && ((!defined(_POSIX_C_SOURCE) && !defined(_XOPEN_SOURCE)) || (_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600)))
+# ifndef __GLIBC__
     err = strerror_r(err, soap->msgbuf, sizeof(soap->msgbuf)); /* XSI-compliant */
     if (err != 0)
       soap_strcpy(soap->msgbuf, sizeof(soap->msgbuf), "unknown error");
 #  else
     return strerror_r(err, soap->msgbuf, sizeof(soap->msgbuf)); /* GNU-specific */
 #  endif
```