Merge pull request #2312 from lioncash/guard

time_stretch: Add missing #pragma once directive

src/audio_core/time_stretch.h

@@ -2,6 +2,8 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
+#pragma once
+
 #include <cstddef>
 #include <memory>
 #include <vector>