WTP sends session id.

FossilOrigin-Name: 32e0df82a8e40e3a3953127ceae58359cdce56696d802e54983f813b00ed1342

src/capwap/cw_out_generic.c

@@ -18,6 +18,9 @@ int cw_put_item(uint8_t * dst, struct cw_item *item)
 			return cw_put_word(dst, item->word);
 		case CW_ITEMTYPE_DWORD:
 			return cw_put_dword(dst, item->dword);
+		case CW_ITEMTYPE_BSTR:
+			return cw_put_bstr(dst,item->data);
+			
 	}
 
 	return 0;