Patch sds.h so that it can be #included from C++
Patch sds.h so that it can be #included from C++

Empty arrays aren't allowed in C++, so a single dummy element has to be added. sds works by scary cast magic so this dummy element is never actually allocated. A #define is used in this patch so in C this compiles exactly the same as before.

bjornbytes/lovr,bjornbytes/lovr,bjornbytes/lovr,bjornbytes/lovr,bjornbytes/lovr