fix in-library uses of exec_()

pyqtgraph/multiprocess/processes.py

@@ -458,7 +458,7 @@ def startQtEventLoop(name, port, authkey, ppid, debug=False):
     global HANDLER
     HANDLER = RemoteQtEventHandler(conn, name, ppid, debug=debug)
     HANDLER.startEventTimer()
-    app.exec_()
+    app.exec() if hasattr(app, 'exec') else app.exec_()
 
 import threading
 class FileForwarder(threading.Thread):

pyqtgraph/widgets/JoystickButton.py

@@ -99,5 +99,4 @@ if __name__ == '__main__':
         
     b.sigStateChanged.connect(fn)
         
-    app.exec_()
-        
+    app.exec() if hasattr(app, 'exec') else app.exec_()