Bugfix: stop the streams in the destructor of streammgr to avoid that the signal generator is detructed while the streams are still running

src/lasp/device/lasp_streammgr.cpp

@@ -251,6 +251,14 @@ StreamMgr::~StreamMgr() {
   // order in which destructors are called does not matter anymore. As soon as
   // the stream manager is destructed, the weak pointers loose there ref, and do
   // not have to removeInDataHandler() anymore.
+
+  // Stop the streams in this phase, otherwise it might happen during the
+  // destruction of the Siggen, in which case we might get calls to pure
+  // virtual methods. This was really a bug.
+  _inputStream.reset();
+  _outputStream.reset();
+
+
 }
 void StreamMgr::stopAllStreams() {
   DEBUGTRACE_ENTER;