fix a deadlock or sporadic crash during shutdown

src/PlugIn.cpp

@@ -20,7 +20,9 @@
 #include <aman/config/IdentifierFileFormat.h>
 
 #include <protobuf/AircraftReport.pb.h>
+#include <zmq.h>
 
+#include "com/ZmqContext.h"
 #include "PlugIn.h"
 
 EXTERN_C IMAGE_DOS_HEADER __ImageBase;
@@ -59,6 +61,8 @@ PlugIn::PlugIn() :
         return;
     }
 
+    ZmqContext::instance().initialize();
+
     if (false == AircraftReporter::instance().initialize(this->m_configuration)) {
         this->DisplayUserMessage(PLUGIN_NAME, "ERROR", "Unable to initialize the reporter-connection to the backend", true, true, true, true, true);
         return;
@@ -67,6 +71,7 @@ PlugIn::PlugIn() :
 
 PlugIn::~PlugIn() noexcept {
     AircraftReporter::instance().deinitialize();
+    ZmqContext::instance().deinitialize();
     google::protobuf::ShutdownProtobufLibrary();
 }