Try to terminate FFmpeg before killing it

common/src/main/java/ctbrec/recorder/download/hls/MergedFfmpegHlsDownload.java

@@ -412,10 +412,13 @@ public class MergedFfmpegHlsDownload extends AbstractHlsDownload {
             try {
                 boolean waitFor = ffmpeg.waitFor(45, TimeUnit.SECONDS);
                 if (!waitFor && ffmpeg.isAlive()) {
+                    ffmpeg.destroy();
+                    if (ffmpeg.isAlive()) {
                         LOG.info("FFmpeg didn't terminate. Destroying the process with force!");
                         ffmpeg.destroyForcibly();
                         ffmpeg = null;
                     }
+                }
             } catch (InterruptedException e) {
                 LOG.error("Interrupted while waiting for FFmpeg to terminate");
                 Thread.currentThread().interrupt();