Fixed bug in M17 modulator and demodulator making them not releasing their audio paths on termination thus locking up the thread on M17 mode re-entering.

openrtx/src/protocols/M17/M17Demodulator.cpp

@@ -189,6 +189,7 @@ void M17Demodulator::init()
 void M17Demodulator::terminate()
 {
     // Ensure proper termination of baseband sampling
+    audioPath_release(basebandPath);
     inputStream_stop(basebandId);
 
     // Delete the buffers and deallocate memory.

openrtx/src/protocols/M17/M17Modulator.cpp

@@ -67,6 +67,9 @@ void M17Modulator::terminate()
         txRunning = false;
     }
 
+    // Always ensure that outgoing audio path is closed
+    audioPath_release(outPath);
+
     // Deallocate memory.
     baseband_buffer.reset();
 }