Hopefully fix Windows build
diff --git a/libs/utils/Threads.cpp b/libs/utils/Threads.cpp
index 6ca2603..00f9943 100644
--- a/libs/utils/Threads.cpp
+++ b/libs/utils/Threads.cpp
@@ -309,11 +309,13 @@
         lasterr = errno;
     }
 
+#if defined(HAVE_PTHREADS)
     if (setpriority(PRIO_PROCESS, tid, pri) < 0) {
         rc = INVALID_OPERATION;
     } else {
         errno = lasterr;
     }
+#endif
     
     return rc;
 }