Fixed Windows build.

Author: mbebenita

src/rt/rust_timer.cpp

@@ -59,7 +59,7 @@ rust_timer::rust_timer(rust_dom *dom) :
     dom->log(rust_log::TIMER, "creating timer for domain 0x%" PRIxPTR, dom);
 #if defined(__WIN32__)
     thread = CreateThread(NULL, 0, timer_loop, this, 0, NULL);
-    dom.win32_require("CreateThread", thread != NULL);
+    dom->win32_require("CreateThread", thread != NULL);
     if (RUNNING_ON_VALGRIND)
         Sleep(10);
 #else