libjack: clean memory correctly in case of error

Signed-off-by: falkTX <falktx@falktx.com>

source/libjack/libjack.cpp

@@ -229,6 +229,8 @@ public:
         fClients.clear();
         fNewClients.clear();
 
+        clearSharedMemory();
+
         carla_debug("CarlaJackAppClient::~CarlaJackAppClient() DONE");
     }