Test phase alignment after device silence and keep diagnostics current

src/call/call_jitter.cpp

@@ -204,6 +204,7 @@ void call_jitter_silence(struct call_jitter* j, unsigned samples) {
     if (!j) return;
     std::lock_guard<std::mutex> lock(j->mtx);
     j->delay.silence(samples);
+    j->diagnostics.phase_samples = j->delay.stats().phase;
     j->timeline.silence(samples);
 }